C++ Tutorial From Basic to Advance

what is going on everybody my name is Bucky Roberts and welcome to your very first C++ tutorial now my guess is that if you're watching this video you probably already have a basic understanding of what C++ is but for those of you guys who don't C++ is a computer programming language it's how you make computer programs computer games so if you're interested in making any of those then congratulations you're in the right spot so before we just start opening any program and trying to write C++ code I want to let you guys know that you need to download and install a few programs first now good news all these programs are entirely free but before we just go ahead and start installing them let me tell you guys what they are and what they do the first program that you're going to need is called an i d-- II this is pretty much the program that allows us to write the code and run it aside from that we need something called a compiler now ago compiler is basically the thing that translates the code that something that computer program is going to understand to something computers can understand so we're going to be typing code and it's going to be easy for us to read and understand what's going on but in order to transfer it to or excuse me translate it to a bunch of ones and zeros that the computer can understand we need that compiler so that being said a lot of people download these separately they download IDE and then they download a compiler but what I'm going to be doing is I'm going to be showing you guys a program that is going to allow you to download and install it all in one big shebang so let's go ahead and open Google and like I said don't worry about paying for anything because this program is entirely free so anyways like I said go ahead and open google and type in code blocks and go ahead and press Enter now the first link that's going to pop up is probably going to be four code blocks org so go ahead and click that and this is the program that we're going to be downloading so of course we need to find the download link you can either click on this one on the left or this one on top doesn't matter go ahead and click on one of those and we see a couple options here download the binary release download the source code or retrieve source code from SVN we're going to want to download the binary release it's the easiest and most simple way to download this program code blocks so go ahead and click download binary release and check it out it gives us all these options now depending on what platform you're running most of you guys will all be running Windows you're going to want to choose one of these options but for those of you running Linux and they also have a Mac version down here you might want to choose these but for most of us we're going to be running this on a Windows machine sorry saying all right now we have it narrowed down to two choices code blocks 1005 setup or code blocks 10:05 a.m. ing W setup what we want to do is we want to download this second one the one that says mi n GW now this version 1005 may be different depending on when you're watching this tutorial and if they updated code blocks but make sure you get the one that says mi n GW the first one is the IDE the second one M mi ng W that mi ng W means the compiler to so when we download this it's going to give us the IDE and remember that's where we write the code at the compiler as well remember the compiler is the program we need so the computer can understand what we're doing so go ahead and you can either download it from barely OS or so excuse me SourceForge I already have it downloaded so I'm not going to click this but go excuse me I guess I'm phlegm in my throat I just drink a fruity stuff freeze from Taco Bell and I ate a taco and that is not a good idea because they should call these things brain freezes brain freezes because that's all that does to you just freezes your brain in your throw and and it puts a bunch of phlegm in your throat but I can't stop drinking it it's a dick thing so anyways go ahead and click this link from sourceforge.net and go ahead and save the file and whenever you save it and open it a wizard is going to pop up and you just have to click Next like 80 different times and then you have code blocks installed so I already installed it so I'm not going to walk you guys through how to do that because it's really simple and I'm not going to act like you guys are dumb and you don't know how to install things on your computer so anyways once you have it installed you have this program called code blocks right here now you probably have it on your all programs you might have it under code blocks what I like to do is right-click it and just send it to desktop and what that's going to do is going to give you a nice little icon on your desktop but anyways once you have it installed just go ahead and double click it and we're going to run a really simple program just to make sure it's working correctly so go ahead it gives you these tips close them out what we're going to want to do is create a new project and you can either do that by creating this new project right here but what I like to do is I like to go up to the file menu and click a new project now it's going to give you a list of a bunch of different projects you're going to want to create what we're going to want to choose is console application this is what you're going to be choosing most of the time this pretty much means a basic program for the computer so just go ahead and select this and press GO and make sure you're working in C++ sees a totally different language we don't want that so C++ go ahead and click Next and now name your project anything you want I'm going to name mine YouTube why not and you can save it wherever you want I might as well just save mine right on desktop it looks good but it really doesn't matter where you save it or even what your name your project just name is something that's easy to remember so go ahead and give your project site we'll go ahead and click Next and make sure you're using the GNU GCC compiler basically everything should be set up by default make sure your settings look the same as mine as long as you didn't hit anything by accident you should be good to go so go ahead and click finish and you see that nothing pops up by default you're saying alright I thought we just created something so how do we see what we just created actually if you click this little plus sign next to sources it shows you that all the files it created for you automatically so go ahead and double click this main and CPP and it shows you or in other words it brings up the file that it created automatically so this is actually the core basics of a very simple C++ program we don't understand what anything means right now but trust me it's a very simple computer program that the only thing it does is it prints out hello world on the screen so to make sure that everything is set up and running smoothly let's go ahead and we need to do something called build and run this now I'm going to be talking about this later but for now I just want to make sure that your computer is set up you installed it and downloaded it properly so go ahead and click this build and run icon right here it's with the little gear and the little green triangle so go ahead and click that and it should you know maybe flash a couple boxes but basically a box should pop up that says hello world and this is all that that program is basically it prints out hello world on your screen so if you build and run this and you get hello world it means that you downloaded it installed it and set up your project successfully so we are good to go so again I know you guys don't know what any of this means or even know how to code one line of code yet I'm going to be going over that in the future tutorials but for now that's all I have for you guys so thank you very much for watching don't forget to subscribe and I'll see you next tutorial what is going on guys it's Bucky and welcome to your second C++ tutorial and in this tutorial what I'm going to be doing is I'm going to be breaking apart this computer program that I ran in less tutorial so if you remember whenever we first created a project in code blocks colorbox already made a very simple computer program for us for us to run and test out just to make sure everything was working and all it did was it printed out hello world on the screen so if you go ahead and build and run this we see that it just says hello world and some other computer stuff that isn't really relevant anyways all this computer program does is print out hello world and before I get into breaking this apart and telling you what each piece does I want to say one thing you would think since computer programs are just made up of a bunch of lines of text that we can learn each line one at a time but computer programs are weird and that this is pretty much the most simple program you can write and check it out there are already seven different lines included here so in order to even write a most basic program you need to code at least seven lines of code so it seems kind of confusing and I just want to give you guys a warning as long as you can get through this video all the rest of the videos are going to be incredibly easy this is the only one where I have to throw a bunch of information at you but still I'm going to break it down as easy as possible and the reason for that is because you need so many things in order to run such a simple program but once you understand the basics everything else is just smooth sailing I promise so let me go ahead and we're going to be getting more in depth in each of these lines but for now let me just give you guys a brief introduction to what each line does let's go ahead and start at the top and work our way down this include iostream line right here this is technically called a preprocessor directive so if you're taking a test if you're watching these stories because you know maybe you're in C++ class and your teacher is kind of confusing you answer on the test this is a preprocessor directive now what that means in read a terms is it pretty much says all right we're going to be including a file in this program that we're going to be using later on so it's going to be including a file i/o stream that we didn't make we didn't make this file but it needs it to run this program later on so that's why it needed to include it again we're going to be talking more about header files later on but for the basics of the story all you need is that to know that this line includes the file that our program needs to use later on now the next line you can see is just a blank line and you may say alright do you need this blank line do you not need it blank lines and spaces you can have a million of them if you want or you can have none of them just like that all blank lines do in programming is they make the program easier to read just with a book or a magazine or newspaper sometimes you want blank lines between your code sometimes you just want your code right under each other it's personal preference um people you know whatever you want blank lines just make it easier to read so whatever is easier for you add as many lines or as less lines as you want and that brings me to another point these tabs to see this is kind of tabbed out or tabbed in it's the same thing some people tap things and make it easier to read this program is just going to run just fine if it's just like that but you know people just like the line certain things up so you'll see later on once we get coding that tabs and spaces and blank lines they don't really meet anything significant they just make the program easier to read so that being said under that blank line is this using namespace STD and believe it or not this does not stand for sexually transmitted disease I like to think that but trust me it doesn't it stands for the standard library and that's another thing that is built in to C++ that is pretty much saying this we're going to be using all the standard things with C++ nothing fancy again we're going to be going over libraries and stuff in the future but basically these two lines include things that are going to need later on this includes a file and this includes something called a library what you know is just a bunch of C++ stuff so with that being said we know that these two lines include things fair enough so now let's get to the meat and on meat and potatoes I guess of the computer programming and that's this this entire thing is called a function now all computer programs are made up of functions and all functions are are things you want the computer to do for example whenever we're making programs later on we're going to make a function to play sounds and we're going to make a function to draw graphics on the screen and as you can see functions are just things that you want the computer to do so every computer program starts with a function called main this is how your computer knows where to start so for example in a couple tutorials we're going to have a function called main and like I said we're going to have another function called play a sound and we're going to have another function called make a ball bounce around on the screen and you're going to have all these functions and your computer's going to say alright you gave me all this stuff to do but how do I know what order to do them in well your computer automatically knows any time it runs a program to start with the main function so that's why it's so crucial to name this function main so in order to make a function you do this you first write what type of data you're going to be working with and what functions typically typically do is they do some sort of calculations for example find the body mass index or calculate the velocity of something well whenever it makes this calculation it usually wants a number back in answer in other words well since we're going to be working with just integers main always works with integers so that's why we need that but again we'll be getting into that later on after that is the name of the function and this one is named main don't worry about these parentheses right now but what we do need to worry about is these little they're not semicolons squiggly brackets I can't I guess they're called curly braces I don't know whatever the heck they are this has an opening and a closing curly brace and in between them you have something called statements now all functions are made up of statements and all statements are basically instructions and each instruction needs to end with a semicolon that's why you see every line inside a function ends with a semicolon for example if you had a function that says make a peanut butter and jelly sandwich one statement would be get out the bread the next statement would be put butter on peace bread the next statement would be put jelly on peace bread the next put them together the last put them in your mouth BAM you now have a function and a series of statements well all this function did the main one said print out something on the screen and return zero simple enough so now you can see the basics of a function how they're made and how every function needs to include statements or instructions so that being said let's break this down even more the first statement is saying this first of all this C out thing right here that's called an output stream object and it's basically used to write characters on the computer screen that's how we are able to type hello world on the computer screen so this is always used in conjunction with this this is called the stream insertion operator this pretty much takes all this stuff to the right of it and prints it out on the screen I mean this is just uh you know it's weird symbols but that's what whoever made C++ they decide to use these weird symbols to print out something on the screen why they did I don't know I have to take it up with them but anyways this is basically how you print out stuff in the screen so this prints out hello world and then this pretty much just means end line or go to the next line so this line right here is pretty much the same print something out on the screen now this last thing I want to talk to you guys about is called the return statement now usually like I said functions will calculate something like body mass index or velocity and when they calculate it it's going to want an answer back so if I had a function that calculated in my weight it would return 1/5 five or 160 depending on if I ate tacos or not today well the main function should always have returned zero and return zero means whenever you return zero it tells your program that it ran fine without any errors for example if you had a bunch of extra text right here your computer program will give you an error and it would never get to this line right here so it will never return zero so whenever it does get to this line it means everything above it ran fine in return zero means you're good to go main ran fine so I know that was a lot of information to give to you guys for just your first tutorial but again like I said every computer program starts with a bunch of stuff that you need to know and we're going to be covering each more of the topics in depth but for now I just want to give you guys a basic understanding of how a computer program is made so if you don't understand everything completely then don't worry you're not alone you will in future I promise but for now thank you for sticking with me and thank you for watching this tutorial and I can't wait to see you next tutorial and if you have any questions don't forget to check out my website the new Boston comm and yeah I'll see you in the next video what's going on guys is Bucky and welcome to your third C++ tutorial and in this tutorial I want to go over a little more about printing text out on the screen now in the last tutorial you remember that we could use that special thing called C out which was technically called the ALPA object and the less than less than sign which was called the stream insertion operator to pronounce X on the screen in the way we did this is we added double quotes after and whatever we print it out in this double quotes like boy I love bacon whatever we put inside those double quotes would just print out on the screen so if we go ahead and we built and run this we saw boy I love bacon right on the screen simple enough but now what I want to go over is just a little more about C out and I just want to make sure you guys understand how it works so each function is made up of these things called statements and typically people put one statement per line of code and remember all statements and with semicolons so say we wanted to print out something else out on the screen will you to write C out less and less than and write something else like and ham just like that so you might be thinking alright I got a feeling I know this is going to do on the first line it's going to print out boy I love bacon and on the second line it's going to print out an ham because you know that's how it appears in our code so that's what it's going to do but if we go ahead and build and run this it says boy I love bacon and ham all on the same line of code every scratching your head saying all right why exactly does it do that the reason it does that B is because when you're using this thing called C out it's called printing it out into a stream and it pretty much takes all your characters and prints them out in the same stream so whenever this stream is done you're not telling it to move to a new line you're saying print out these characters and then stop right at the end of the sign so then this stream starts printing out and again you're not telling it anywhere to move to a new line computer programs are very picky and they need to be told exactly what to do so in order move to a new line we need to add a special symbol I guess you would say and the symbol is this first of all you need to add another stream insertion operator and you can go ahead and write E and DL what this means is end line and now when we go ahead and build and run it check what happens it runs boy I love bacon and then it runs in line and before your stream insertion operator would be right here but now since you set end line and go ahead and end this line and it moves it to a next line so basically all you have to remember is anytime you want to move to a new line use the character n L which is code word for end line now if we're saying alright that's easy enough to remember so let me go ahead and show you something that might be even easier for you inside your quotation marks if you go ahead and add backslash n this is basically the same as adding a newline backslash n is the code I guess that all is code for go to a new line so now it's going to say boy I love bacon and then it's going to come across this thing called backslash and it's going to say hold on what is this backslash n oh I know what it is it's the symbol to move to a new line so this is basically just an alternative way to move to new lines the only difference is when n L you needed to add another insertion operator and then right end L right there with a newline you write it inside the quotation marks because it gets interpreted in different kind of ways so let's go ahead and build and run this and just verify that yep boy I love bacon newline and ham so again like I said whenever you want to print text out on a new line you have to be very specific with C++ and tell it exactly what to do and you can do this either using the NL or the new line that goes inside the quotation marks so aside from this you might think in alright so I print this out and I got this on next line but what if I wanted a blank line in between these two well all you would have to do is write new line new line and then when you go ahead and you build and run this oak say alright boy I love bacon new line new line and then it printed out and ham simple enough pretty cool huh and I guess one other thing I can show you is if you go ahead and do see out insertion operator arm you can do things like this boy new line i new line love new line bacon new line so you know you're not only limited to you know one new line per statement you can have multiple new lines in a single statement so now it says boy I love bacon pretty cool huh so that's all the basics I wanted you guys for this tutorial again I wanted to stress how to print out text on the screen and also the stream insertion operator it's basically this each stream insertion resumes it's printing out wherever the previous ones stopped so if you want to move it to a new line you need to use one of these new line symbols either NL or new line so that's all I have for you guys in the soil now you should be a pro at printing texts out on the screen so you know we're not ready to bundle up this program and sell it to Microsoft yet but hey let's start so thank you guys for watching if you have any questions go to my website the new boston comm and ask me on my forum so thank you guys for watching and I uh I guess I'll see you next video what is going on guys welcome back to your fourth C++ tutorial and in this tutorial I'm going to be going over something called variables because variables are such a huge part of C++ I can't stress this enough so let's go ahead and tap into our memory banks and try to remember back in like seventh grade when you first start learning about variables and if you can't remember let me give you a brief history lesson variables are basically just placeholders that's all they are so let's go ahead and say we had a variable named X and we set it equal to bacon well then whenever we would have a sentence like Bucky loves X we knew that x equals bacon so this man Bucky loves bacon simple enough so let me give you guys another quick example say X was equal to 7 so then when we had a statement like 5 plus X we knew that this meant 5 plus 7 simple enough so as you can see a variable is basically just a placeholder now let me go ahead and show you guys how to make variables in C++ and C++ in order to make variables you go ahead and first write the type of variable you're going to be working with now I'm going to be going over datatypes later but for now I want to give you guys one data type and that's I and T this stands for integer and an integer is pretty much like a whole number like 683 540 it's a number without a decimal place so now that you gave C++ the type of data you're going to be working with you need to go ahead and name your variable go ahead and name it anything you want I'm going to go ahead and name mine tuna so now it has a type and a name so now all we have to do is use the equal sign and set it equal to a value so since this e has to be equal to a whole number let's set equal to 6 it doesn't matter what whole number you set equal to but I just like 6 it's easy to type so now we have the variable tuna and C++ knows that it's an integer and it's equal to the value of six so now what can we do with variables well just like we can print out text on the screen we can also print out variables just as easy so if you went ahead and said C out and just go ahead and print it out tuna we can go ahead and build and run this and it would print out not the word tuna but it would print out six just like that so that's pretty cool and that's the basics of variables and how we can use variables in C++ and actually and this is sort of what I was planning on doing is building a simple calculator um let me go ahead and I guess I have time for this let's go ahead and make two variables and I'll show you guys another cool thing that you can do the C++ let's go ahead and make int we'll call make a variable called a and we'll set it equal to four let's go ahead and make another variable called B which is of course an integer because that's the only type we know right now and we'll set this equal to you know 21 or something doesn't matter as long as they're both numbers now let's go ahead and make another variable called a sum and this sum is going to be equal to a plus B so now you can see aside from let's go ahead and yeah that's good enough so now you can see that aside from just assigning variables numbers just like that you can also use basic arithmetic to set variables equal to another value as well so now the value of 25 a plus B is going to be equal to sum so now if you go ahead and print out C out some and we go ahead and we build and run this check it out it prints out 25 on the screen pretty cool huh so again in this story I want to show you guys that in order to make variables go ahead and write the datatype what do you want the name of the variable or excuse me what you want the name of the variable to be and what you want the value of variable to be and then aside from just assigning variables basic values you can also use basic arithmetic like a plus B on B minus a you could done that let's see if you had B minus a let's go ahead and see what the value of that is 17 so again you can go ahead and set variables equal to basic arithmetic using other variables and you can even do this sum equals 48 minus 7 again this isn't really the sum anymore it's more of a proud buzz and not the product not the quotient the difference there we go that's what I and there we go I got it so again you understand the basics of variables that's what I'm trying to stress so in the next tutorial what I'm going to be doing is I'm going to be showing you guys how to make a very basic calculator and this is the first program we're going to be building they actually interacts with the user and it's going to be awesome and you needed to understand variables before I could show that to you guys so that's why I had to go over this story but for now thank you guys for watching don't forget to subscribe and don't forget to check out my website the new Boston comm it's awesome so anyways thank you guys for watching and I'll see you next video alright guys welcome back to your fifth C++ tutorial and in this tutorial since we now have the knowledge of variables within C++ let's put that knowledge to use so let's go ahead and make three variables right now but I'm going to be making them a little bit different than before so in the last tutorial we had a variable like a and you said equal to the value like 54 simple enough but I want to tell you guys that whenever you first create a variable you have the option of assigning the value then or assigning the value later on such as a equals 54 this is perfectly fine and you can do it this way so whenever you first create a variable and you don't assign the value this is called declaring the variable declaring is just another name for creating the variable so let's go ahead and create three variables and by the way I'm going to be making a basic computer program where the user enters two numbers such as like 2 & 3 and the computer is going to add them together and it's going to give them the answer which would be 5 so int a I'm going to have a variable called a and I'm going to have another variable called B and what we're going to be doing is we're going to be calculating the sum or in other words when you add the two numbers together the answer of that and storing it in a variable called sum so we don't have any of the values yet so that's why we can't fill them in the users going to be entering the values for us so the first thing we want to make in this program is just a little prompt on the screen the tell the user to enter a number and we do that using C out and we just write enter a number pause and then let's go ahead and write newline and now we need a way for the user actually to input information from their keyboard so here's a neat little thing I can tell you see out took information from your computer and output it to the screen but anytime you want to take information from the computer or excuse me from the user and give it to the computer you need to use C I n so C out basically takes information from the computer and gives it to the user cien takes information from the user and gives it to the computer so if you're right CIN and by the way if you're taking the test this is technically called the input stream object and the little greater than greater than sign is called the stream exaction extraction operator so you know make sure to fill that out on your multiple choice if you're watching this in the C++ class or something so anyways you can see that this is different from the C out for two reasons first of all it's C in instead of C out and also your arrows face the opposite way that's because you're giving information to the computer instead of the computer giving information to you so now what we can do is we're going to enter a number and whatever number we're enter we need to give it a place to store that number well we already have a variable right here so let's go ahead and use that and use the variable a so check this out it's going to allow us to enter enter a number and whatever number we enter it's going to be stored in the variable a so for example if we enter the number three a is going to be equal to three simple enough so now that we have that variable taken care of we basically need to do the same thing again with the other variable B so C out will say enter another number and just go ahead and we'll just make a new line to make the program easier to read and use that C n again but now when they enter a number we want that value to be equal to the variable B so they're going to enter two numbers one's going to be equal to a the other is going to be equal to B so now for the sum we don't want them to you know enter value for the sum we want to calculate that ourselves so in order to do that just go ahead and write sum equals a plus B and now what your computer program is going to do is it's going to say RA I'm going to grab the very excuse me I'm going to grab the value you put in for a and I'm going to grab the value you put in for B and going to calculate that and I'm going to store that in the variable sum so for example if you wrote ten and fifteen it's going to say alright grab ten grab fifteen calculate the sum of it which is 25 and store it in a variable called sum so now the sum is equal to the answer and all we have to do now is print it out on the screen so see out will just write the sum of those numbers is is it the sum of those numbers are or some of those numbers is I think it is because it's one song and again anytime you want to add more than one line of text you could do it like this you could write a new line and then print this out on another line but I want to add on the same line so I'm going to go ahead and add another insertion operator just like that and just go ahead and write sum and then add another one and just go ahead and write end line just so our program looks nice and neat so basically well let me go ahead and run this and I'll talk you guys through it after I run it our computer program says enter a number Huss I'm going to enter 50 and then go ahead and press Enter once I press enter 50 is going to be stored in the variable a it says enter another number I'm going to enter 32 then I'm going to press ENTER and that 32 is going to be stored in the variable B then it's going to make our calculation and print it out on the screen the sum of those numbers is 82 50 plus 32 is indeed 82 so remember what we did is basically this we made three variables that we're going to be using later on the first thing it said is just basically a prompt enter a number then we entered 50 it stored 50 in the variable a using CN again CN is a way that the user can give information to the computer program instead of the other way around so now a is equal to 50 it gave us another prompt and we typed in 32 now B is equal to 32 so in order to calculate the sum we took the sum variable and set it equal to the sum of 50 plus 32 so now some holds the value of 82 or 83 whatever I typed in I can't remember and then all we did is we printed it out on the screen and again we could have wrote three different statements for this one C out for this one C out for this one C out for this but in order to save us some time we can actually use this operator right here and print everything out on one line so that is why our program ran the way that again let's go ahead and run it one more time enter a number 44 and 76 hit enter that some of those numbers is 120 pretty cool huh so that's how you build a basic calculator in C++ using variables and C out so now that you got that done on we can begin moving on to the next topic which is I don't know but trust me it's going to be amazing so um you study this and once you understand the basics of variables and CN you're ready to move on to next video so for now thank you guys for watching don't forget to subscribe and I'll see you in the next tutorial what's going on guys it's Bucky and welcome to your sixth C++ tutorial and in this tutorial I want to go over some concepts with variables that are definitely going to help you later on so the first thing I want to go over is this you remember in the last story where I told you guys that there are basically two different ways to create variables the first way is to create a variable called tuner or something and set it equal to value like 43 all on one line simple enough easy to understand well what I also told you guys you can do is you can declare aka create it on one line and set it equal to a value on another line such as that they're both perfectly acceptable ways to do things the one thing I want to stress is that whenever you do this way declare on one line and set equal to value on another line you don't need to write what type of variable it is again once you give C++ the information of what type of data you're working with you don't need to list it every time you're working with the variable C++ will remember that information and you know it'll keep it so whenever you're working with tuna later on you don't need to explicitly write int and actually you can't or L so to give you an error message so just make sure that you know just remember that don't write int twice on same variable so aside from that let me show you guys this in tuna equals 99 so later on and I didn't tell you guys this but what you can do is if you set tuna equal to something else like 76 whenever your computer creates a variable it sets aside a piece of memory to store that value in this case 99 well whenever you create or excuse me whenever you use that variable again and set it equal to a new value where your computer is going to do is it's going to wipe out the old value in order to make room for the new value so now you said all right we have a variable called tuna and that's equal to 99 well now we have a variable called tuna and we want to set this equal to 76 well all right so we're going to try to print out tuna and our computer is going to say alright should I print out 99 or 76 well since we created one originally that was 99 and then we overrode it to make it 76 it's going to print out 76 so let's go ahead and build and run this and see what we get 76 so basically whenever you have a value it's placed in a memory location and then whenever you give that variable a new value it's going to overwrite the old value and put it in the same location so I just want to tell you guys that this is how you can overwrite variables so if you're expecting 99 and you got 76 this is why so that's actually all I have for you guys for this story again the two things I want to stress is whenever you're creating a variable you only write the type once you don't need to write it every single time and then whenever you need to reassign a value you just go ahead and write the variable name and not the type again and also whenever you're overwriting a variable you use the variable and it's going to be equal to the latest value so whenever you you know set this equal to 76 it's going to wipe out the 99 and use the 76 so I just wanted to stress those you know a couple memory concepts so then whenever we're building programs later on you might have a better understanding of how it works so for now that's all I have for you guys in the next tutorial you know how I said that we're going to be going over arithmetic like how to add two numbers together well there's actually a bunch of different arithmetic operators that we need to learn and that's where we're going to be covering in the next tutorial but for now thank you guys for watching don't forget to subscribe and I'll see you next video all righty guys welcome back to your seventh C++ tutorial and in this tutorial as promised I'm going to be going over basic C++ arithmetic now I don't know I think it was like tutorials go I gave you guys a variable and I showed you guys that instead of just setting it equal to a plain old value like this you can use basic arithmetic like 4 plus 6 and then when you go ahead and you print it out X or anything like that it actually calculated the value and printed out the answer so go ahead and run this and you see that X now equals 10 4 plus 6 so aside from addition I want to show you guys all the arithmetic operators that you can use and they're a little bit different than you might expect so let's start with the easy ones first the first one is subtraction and of course like 8 minus 4 this would be valid if we go ahead and build this we saw that the answer would be 4 so addition subtraction easy enough but also aside from addition subtraction you can use multiplication but make sure not to use X like that because that will mess up in order to multiply in computer programming use the asterisks and that's the symbol above the eight on your keyboard and what this is going to do is multiply these two numbers eight times four so now if you go ahead and run this we should get 32 and check it out 32 just like that so the well let's go ahead and before I go over this let's go ahead and go over division in order to use the vision in computer programming let's go ahead and take 81 divided by 3 division the symbol for this is the forward slash so let's go ahead and take 81 divided by 3 and we get 27 just like that simple enough but check this out what if we have something like 81 divided by 2 well this I mean it should be 40 but it has a remainder of 1 so let's go ahead and try to build and run this and see what we get well it just has 40 and that's not entirely right because it should have a remainder of 1 with it so we're saying all right we're working with integers right here and we any other data types so how can we get that remainder well whenever we want to use the remainder we need to use something called the modulus operator and that is the percent sign like this what this is going to do is it's going to give you the remainder of the answer it's not going to say 40 remainder one it's just going to give you that one so let's go ahead and build and run this and you can see that whenever we do 81 modulus 2 it's going to give us the remainder which is 1 so let me show you guys a better example on maybe 24 modulo 7 well we know that 21 or excuse me 24/7 is 3 with a reminder where the remainder of 3 so let's go ahead and build this in again it doesn't say 3 remainder 3 it just says the remainder which is 3 simple enough so now that we know all the arithmetic operators I can begin teaching guys about order of precedence now aside from just you know one number of rithmetic operator another number you can have complex calculations like 6 times 4 plus 8 times 4 plus 9 divided by 20 and if we go ahead and build and run this let's see what we get 56 birthday in our a so what order is just doing this in is it doing 6 times 4 and then plus 8 or is it doing you know 4 plus 8 and then times that by 6 because depending on how you do it it's going to come out with a different result so the basics is this if you remember way back in like seventh grade math you know something called your associative property and that's pretty much this anything that's in parentheses gets done first if you don't have any parentheses it goes like this it does all the multiplication in the vision which would be this this and this it's going to do that first and then it's going to do you're dissin addition and subtraction if you don't have if you know if you just have like four plus eight plus seven um you're saying all right then is it going to do a plus seven first or four plus eight first it really doesn't matter it comes out the same either way the only time you have varying answers is when you have like four plus three times seven for example if you did four plus three it would be 7 times 7 would be 49 but whenever we run this whoa easy box we get 25 why is that because it uses the associative property it actually multiplies first which is 7 times 3 and that's 21 plus 4 which is 25 so again if you want to explicitly say 4 plus 3 first you need to surround that in parentheses so now whenever we build and run this it's going to run your parentheses first and say our a 4 plus 3 equals 7 times 7 equals 49 so remember the rule is this parentheses first then your multiplication in the vision and then your addition and subtraction so remember that and if you get confused it's called the associative property you should have learned it in like eighth grade math or ninth grade math or maybe 7th grade I don't know I can't remember it was a long time ago for now that's all I want to talk to you guys about basic arithmetic and how it works in C++ so for now that's all you guys get so thank you guys for watching this tutorial if you have any questions go to my website the New Boston calm and click on forum and you can ask me there so one last time thank you guys for watching don't forget subscribe and I'll see you next video what is up guys is bucking welcome to your eighth C++ tutorial and in this story I want to talk to you guys about something called the if statement now the if statement is a way where we can have our program make very basic decisions what we're going to be doing is we're going to be giving our computer program a test and it's going to run that test if the test is true then it's going to run a certain bit of code if the test is false then it's not going to run any bit of code so depending on that test depends whether we run coda or not so it sounds confusing but it's actually incredibly simple so let me go ahead and I'll show you the syntax for if statement right now the syntax to make an if statement is I F you just go ahead and type the word F and then go ahead and add parenthesis now inside our parentheses is where we're going to be making our test now after those parentheses go ahead and add curly braces now this is called the body of the if statement and now here is where we write the code to run if the test is true so let's go ahead and make a simple bit of code let's go ahead and just write like C out armed lucky is awesome so if our test is true it's going to print out Bucky is awesome on the screen if the test is false it's not going to print out anything so let's go ahead and let me talk to you guys about the different types of tests the first test I want to show you guys is the greater than test and this simply tests if one value is greater than another value so if v is greater than three go ahead and run this code so 5 is indeed greater than 3 so this is true so whenever we build and run this it's going to say Bucky is awesome pretty cool huh so now let's go ahead and make something like umm is 1 greater than 3 so it's going to test this is 1 greater than 3 well this is actually false 1 is less than 3 so it's not going to run this bit of code so go ahead build and run this and as you can see it did not print out Bucky is awesome on the screen how sad so of course we have the greater than test we obviously have the less than test one lesson three well now this is going to be true so it's going to print out Bucky is awesome on the screen so let's go ahead and run this and indeed it prints out Bucky is awesome so aside from greater than and less than we also have these two tests greater than or equals two so whenever we tested whether three is greater than three this test is going to be false because three is not greater than three three is actually equal to three well if we want to test if three is greater than or equal to three we use greater than with the equal sign after it so now whenever you run it is three greater than or equal to three yes three is equal to three so print it out Bucky is awesome so aside from that we also have the less than or equal to so if you know is one less than or equal to three yes one is less than three so it's going to print out Bucky is awesome so again what I want to show you guys is that you have greater than less than greater than or equals two and less than or equals two so now those are called the relational operators we also have two more tests that we can do and these are called the Equality operators this is a really simple test it tests whether one value is equal to another value or if one value is not equal to another value so in order to do this go ahead and write is three equal to equal to three and you might be thinking all right why don't I just use one equal sign why didn't they make it that way well whenever we were creating variables such as like int x equals eight the one equal sign the single equal sign is assigned for creating variables and assigning values so that's why I decided that two equal signs was sufficient for testing so remember a common mistake is to put one equal sign in there and you're going to get an error or something terrible is going to happen so whenever you're testing you need two equal signs so let's go ahead and run this test is three equal to three well yes it is so it's going to print out Bucky is awesome I'll give it another test like is seven equal to three well no it's not so it's not going to print out buck is awesome so that is one test is called the equal sign equal sign or equal to test and there's one more test I want to go over and that's explanation point equal sign and this is the key word for not equals to so is 8 not equal to or in other words is 8 different than 8 well no it's the same so it's not going to print out everything is 10 different than 8 well yes it is so that's going to be true and it's going to print out Bucky is awesome so that is all the tests that I have for you guys and that's all the tests in C++ again to recap one last time greater than less than greater than or equal to less than or equal to equal and not equal so now that we know all those tests I probably should tell you guys this people typically don't in by people I mean computer programmers computer programmers typically don't just test two numbers against each other they usually have variables that they test against each other like int a equals 98 int B equals 76 and then they test something like is a arm greater than B well if we go ahead and run this 98 is indeed greater than 76 so of course that's true it's going to print out Bucky is awesome and aside from that you either have two variables to test or you have a variable and a value like is 98 greater than 5 something like that we can actually mix variables with values and that would be true as well so again you can either have two values in here two variables or variable on one side and value on another side pretty cool huh so that's the basics of again relational operators are the greater than and less than one and equality operators are the equals equals in explanation point equals so now that we know how to make a basic if statement again to recap one last time if your test and then the body and it's going to run the test and if that code is true is going to run the body that's the basics of a if statement now that we understand that we can begin enhancing our program a little bit more so in our next tutorial what I'm going to be doing is I'm going to be having the user enter two numbers and we are going to be comparing those numbers and depending on what numbers they entered run a certain bit of code so now as you can see we're just building and building to our knowledge of C++ to make better and better programs so don't skip over if statements because it's a huge part of C++ so for now that's all I have for you guys so thank you guys for watching in the next tutorial we're going to be building that calculator thingy so it's going to be awesome so thank you guys for watching don't forget to subscribe and don't forget to check out my website what's going on guys it's Bucky and welcome to your ninth C++ tutorial and in this tutorial I'm going to be talking more about functions now I talked about this a little bit in like I don't know a couple tutorials ago but I want to talk about it again because I really want to stress what functions are and why they are useful in C++ programming so if you remember a function is basically a computer program is made up of a bunch of functions right now we have one function right here and basically the job of a function is to do something so inside function we can give our program a bunch of separate instructions all followed by a semicolon so our main function that we already learned is the starting point for every computer program every program starts with the function main so this is one function right here but let's go ahead and create another function and in order to do that go ahead and separate from your main so before we're coding everything inside the main function but now we want to create another function so go outside main right here now the first thing that we need is a return type and this is whenever people build functions they usually make a calculation and give you back something for example if we had a function to calculate the speed of my car it would give me back a number if we had a function to UM calculate my weight it would give me back a number well sometimes functions make calculations and sometimes when they don't make calculations just as like printing something out on the screen it doesn't really need to calculate anything so sometimes functions are going to return a number to you in that case you would use int and sometimes they just do stuff like print something out on the screen and don't return any answer to you whenever a function doesn't return anything to you just go ahead and put void and this means you know function just go ahead and do your thing and I don't want anything in return so the very first thing you write is the return type of the function so this one you see it return a number but this one is just going print something out on the screen so it's going to return void so after this you go ahead and you name your function this one is named mein and you can actually name it anything you want this function is just going to print something out on screen like I said so I'm just going to name it print something pretty dumb I know but hey it's my function I can do what I want so after this you see that I added two little curly braces and those are actually called parameters um whenever your function needs additional information you add parameters but we're going to be covering this in next tutorial for now just remember to add them and add nothing in between them trust me I'm going to be covering this in next tutorial and I'm going to make real easy to understand but after these parentheses go ahead and add two curly brackets and just like I said before this is the body of your function for example if you had a function called make peanut butter and jelly inside your body you would have a set of instructions like get out the bread next instruction put peanut butter on one slice next instruction put jelly on one slice lastly eat it well in the body of our function we give it each instruction about what we want this function to do so in our function called print something the only thing that we want this function to do is print something out on the screen easy enough we already know how to do that so let's go ahead and see out oops there we go and what are we going to print out on the screen just right like ooh I am text on the screen it's very feminine function we have here but anyways then just go ahead and end the line simple enough so now whenever we use this function we're going to whenever you use a function it's called calling the function why they did that I don't know but um just remember whenever I say call the function I basically just mean use the function so whenever we call this function all it's going to do is print out ooh I am text on the screen simple enough so let's go ahead and remember since our computer program starts with main we need to tell it in main that this is the function that we want to use so in order to use or call a function all you do is this just go ahead and write print something empty parameters and a semicolon so again anytime you want to use a function just go ahead and type the name of the function empty parameters and a semicolon but check this out whenever we try and build and run this we're going to come and get an error this with this little red rectangle means you can't read my error message because it's down here but says printing something was not declared in the scope and you're saying all right what did we do wrong because Bucky told me that this function is built perfectly which it is but whenever it tried to call it or use it right here it didn't understand what was going on so why is our compiler kind of confused well the reason is this computer programs work from the top down it starts at the very top line and it runs downward until it gets to the very end and then it quits so whenever our computer program was running it said this all right include this file done use this done okay now start with main print something Oh what the heck I never seen that before is this a function or trying to make a variable or what the heck are we doing I don't know what this means well that's because whenever we created our function we created it after we use that we need to tell C++ before we use our function that is actually a function so we have a couple ways of doing this probably the easiest way is just to do this go ahead and cut it and then above your main go ahead and paste it and now C++ is going to think like this all right I'm going to include this simple enough I'm going to use this easy enough and oh you made a function called print something now okay I'll remember that so now whenever I call my main and I come across this thing called print something I know that it's a function that you created so that's why whenever I build and run it now it's going to run perfectly without any errors so that is basically how a computer program works first you need to tell it that you are actually creating a function before you can use that function so if you just try and use it it's not going to know what it is if you didn't create it first sever saying all right I just remember to create all my functions before I use them okay you can do that but let me give you an alternative method of doing this if for some reason you like your main at the top and you like to create your functions after well we already know that whenever you try to run this we're going to get an error but there is one thing that you can do and this is called function prototyping and all this is is this trust me it's the easiest thing ever go ahead and select your a turn type your function name and the parentheses and go ahead and copy that now above your main and under your using go ahead and paste this this is called the function prototype and it's pretty much a copy of your functions header and it basically is saying this alright whenever you run this program now go ahead and include this include this and then we're going to this is called prototyping a function this is pretty much telling our C++ program this alright later on you're going to come across something called print something now whenever you come across it we don't want you to freak out like you have before something us a whole bunch of error messages what we're telling you right now is we created a function called print something but you have to go find it and C++ is going to say oh all right now whenever I try to run my main and I come across this function instead of giving you error message I'm going to know that this is a function that you have somewhere in your program so I'm not going to freak out I know this is a function I know to handle it accordingly so check it out whenever you try and build and run this it works perfectly so that is why you need to do one of two things before you use your function in main one you can prototype it or two you can just go ahead and make your function before main either way whenever you run this function in main it needs to know beforehand some way that this is a function so those are your two different ways of doing that and again in order to create a function go ahead and type the return type the function name and the parameters and again I'm going to be talking about these parameters in the next tutorial so as long as you understand this and the basis of how to create a function and how to use them in main you're ready to move on to the next tutorial so thank you guys for watching don't forget to subscribe and I'll see you guys in next tutorial what is going on guys is bulky and welcome to your tenth C++ tutorial and in this tutorial I'm going to be teaching guys how to create a function that uses parameters now a parameter is quite simply additional information that that function needs in order to work so let me give you guys a quick example of this say you made a function to calculate the age of someone how old they were well some additional information you would need before you can calculate that is what year were they born and once you have this information you can calculate their age so let's go ahead and now that we understand why a function would need additional information let's go ahead and create a simple and excuse me a simple function to use additional information so let's go ahead and create a function that just prints out Bucky's favorite number is blank um we might see Bucky's favorite number is 20 Bucky's favorite number is 68 Bucky's favorite number is 99 well since we don't know what my favorite number is yet we're just going to go ahead and put a variable in place for that number so since this isn't going to be making any calculations really we can just go ahead and use a void because that means return nothing so name your function anything you want I'm just going to name my print crap since that's all it's going to do print crap out on the screen and before we just added these empty parentheses when nothing in between them and then we coded the body right here well whenever we use a parameter you actually put that information right in your parentheses and check this out you know how I said we didn't know what that number is yet and that's the additional information that we need well since we don't know what it is yet we just go ahead and we set it equal to a variable and since this is an integer we go ahead and sequel to the variable int X you can name your variable anything you want but I'm going to name mine X because it's really simple easy to work with so now we can go ahead and we can add the body of this function and all we're going to do in this function is pronounce screen Bucky's favorite number is that I spell everything wrong yup yep good to go Bucky's favorite number is X and then just go ahead and that line and now when our function runs is going to run something like this if we say that our favorite number is 20 it's going to say Bucky's favorite number is 20 if we say that our favorite number is 10 Bucky's favorite number is 10 so we can run this function a bunch of times and give it a different piece of information each time and it's going to work so let's go ahead and remember in order to use a function in your main you just go ahead and you type the function name and then you add your parentheses and your semicolon at the end but whenever your function needs an additional piece of information you need to give it that information inside the parentheses so we know for making our function that it needs one integer in order to work so let's go ahead and in inside these parentheses give it one integer 20 so now what it's going to do is well let me go ahead and run this and show it to you guys Bucky's favorite number is 20 all right so what happened is this we said all right C++ program we want to use this print crap method well it said all right in order to use this method I'm going to need one integer so we gave it the integer 20 so then whenever in this function it came across the variable X it just substituted 20 for that so whenever you're making parameters you first need to list what type of data and also a variable name so then whenever we give it that variable its substitute that variable for X later on in the program so for example let's give it one more example like 854 well now we run it and it says Lucky's favorite number is 854 and that's the beauty of parameters and functions it doesn't need to be the same every time so that's why you can use variables so again what we did is we created a function and it needed an additional piece of information which was an integer and since it didn't know the value yet it just went ahead and set it equal to a variable then later on in the body whenever it came across that variable and knew whatever value you told it to substitute for X that's what value is substituted for X so we can run this 100 times with a hundred different values if we want it's going to substitute it for X each time and use that information to plug it in so that's the basics of how you use functions with parameter again whenever you're creating a parameter use the datatype and a variable name and whenever you're using the function don't forget to pass in or give it whatever information it needs so that's pretty cool was simple enough we understand that but in the next story what I'm going to be teaching you guys is how to use function that use multiple parameters what if a function needs more than one piece of information in order to work well I'm going to show you guys how to do that too and it's a little different than this so you definitely want to watch that so once you understand this and understand the basics behind functions and parameters you're ready to move on to the next tutorial so thank you guys for watching don't forget to subscribe and I'll see you guys in the next video oh hey guys what's up welcome to your eleventh tutorial and in this tutorial I'm just going I'm not going to do this whole tutorial in song maybe maybe another tutorial but I'm not really in the mood this time so anyways and this is Toro what I'm going to be teaching you guys is how to use functions that require multiple parameters so let me give you guys a quick example of function that might require multiple parameters if you were making a calculator and you wanted the user to enter two numbers well it did it doesn't exactly know what those numbers are yet so we go ahead and we use these numbers as parameters and functions so as you can see instead of just a single piece of information it might need two numbers or eight numbers or 20 numbers so in order to use multiple parameters in a single function let me show you guys how to do that so let's go ahead and make that program right now that just goes in adds two numbers together well we can't use void because right now it is making calculation it's going to calculate two numbers find the sum of them and return to the return to us the answer so let's go ahead and say all right since what you're going to be returning to us is an integer go ahead and type int and now what am I going to name my function add numbers simple easy pretty clear so now we go ahead and make our parameter list and body list here's what I do before I add in my parameters I don't know why but you know I just do it so what we want to do is we already know that we can use one parameter by going setting the datatype and giving it a variable name cinches int X well we know that this function is going to need two numbers we already did one so how do we say we want to use another number as well well anytime you use more than one parameter you have to separate it with a comma and then you give it another piece of information that's going to need so it's going to need two numbers one is going to be called X and is going to be called why so let's go ahead and now we have a function that takes two extra pieces of information so we're going to be getting it to integers x and y so now let's go ahead and use those numbers somehow so what we're going to be doing is let's go ahead and make another variable called answer and this is just equal to the values of X plus y so say that the user passed in two numbers on five and six well what we're going to do now is say all right five equals x six equals y so answer equals eleven so once we have that answer calculated all we need to do now is we need to return it and this pretty much means give it back so in order to return anything you just go ahead and write return and then what you want to return well just return the answer so a return value is basically once you make your calculation the final calculation that's what they get back so in main we return zero because computer programs know whenever you get zero back this means that your computer program ran successfully well for this one we want to return the answer because that means that we calculate the answer so that's where we're going to return back so now when we're using our function we can just go ahead and print out that value using C out and then go ahead and write add numbers and then go ahead and write whatever numbers you want to add and just like before whenever we were creating our function we had to separate these variables with a comma whenever we're using on this function later on in our main program we separate the values we're passing it in with a comma as well so 43 is going to be equal to X and 86 is going to be equal to Y so let's go ahead and go and run this and check it out 129 pretty cool huh so what happened is this we said all right we want to print out the return value of this right here so we can't just go ahead and do this because this is going to go ahead and calculate it but it's not going to print anything out on the screen so actually made that calculation but nothing's printing out so in order to print that out that's why we need that see out to print out the return value of this so anyways what we did is we said this all right we want to use this add numbers function right here but it needs two integers in order to work and needs a x and a y so we said all right you want two integers you got it you got a forty-three and an 86 let's make some magic happen baby so it took that 43 plug the end for X and 86 plug the end for Y and it's stored that value or excuse me to store the sum of the calculation in a variable called answer and the answer was like I don't know what it was but it took the answer and it returned it back to you so says all right this is basically equal to 129 so this right here is pretty much just a different way of saying 129 so I'm going to print out 129 and that is how you use functions with multiple parameters for example if you wanted to add four numbers together it would be the same thing in X&Y and it's a and B and then you just go ahead and use those values just like before so plus a plus B and then later on when you needed more information 32:43 again why I'm doing this I just want to show you guys that you're not only limited to two parameters you can have as many parameters as you want you just have to remember to separate them all with a comma so whether it's 2 3 or 100 remember to separate them all with the comma in here and also when you're actually using the function out here so now you understand the basics of what a function is and how to use multiple parameters single parameters you're pretty much a pro with functions now so once you understand this you're ready to move on to my next so thank you guys for watching don't forget subscribe and I'll see you guys later what is going on guys and gals welcome to your 12th C++ tutorial and in this story I'm going to be giving guys an introduction to classes and objects now classes are basically an easy way to group all your functions and variables and the group a bunch of stuff together for example people like to group similar functions together in the same class for example if you had a bunch of functions you know maybe working with temperature or you had a bunch of other related functions you might want to group them all in the same class and makes them easier to work with later on so then you know if you have like a thousand functions you say all right where are all my temperature functions because I need them now oh they're in my temperature class so that is kind of the usefulness of classes and the basics behind that so let's go ahead and in order to create a class we go ahead and make sure you're outside your main first of all I want to say that so I'm going to create mine before my main and in order to do this go ahead and type the word class and now after this go ahead and add a space and name your class now people typically name their class with uppercase letters and I'm going to name mine Bucky's class just like that and now go ahead and add curly braces in a semicolon at the end now everything all your functions all your variables all your crap goes inside the body of your class right here so basically all your crap that you want to go in the class goes in the class body just like that and I believe whenever you create a class is called declaring a class but you know if your teacher ever asks you to make sure you say that they'll probably be impressed so before we start adding a bunch of functions itself I want to talk to you guys about something called an access specifier now sometimes you want to make functions that you can only use in your class and sometimes you want to make functions that anybody can use outside your class so if you want for example the main to be able to use your functions inside your class you need to make your functions public if you don't want main to be able to use the functions inside your class then you do something called private but we're going to be going over that later for now just remember whenever use the public access specifier it says that you can use it outside of the class so in order to use that public access specifier just go ahead and type public with a colon not semi colon just a regular colon and this means that anything you put after this you're able to use it outside of this class so if you didn't have that then you would only be able to use your stuff right here and what's the use of that if you need to put it in main so anyways make sure you add public it's called an access specifier if you're taking you know C++ test or something so now let's go ahead and we create a function just like before I'm just go ahead and print out something on the screen so it's not going to make any calculation so it's just going to print something out so void I'm going to name it cool saying and it's not going to take any parameters a really simple function here and all it's going to do is print something out on the screen now I got to think of a cool saying um preaching Wow totally messed that up preaching to the choir I think that's how you spell choir not sure hope I don't look like a fool in front on my subscriber so now just go ahead and end line and so all this function is going to do is print out preaching to the choir on the screen simple enough so now you're saying alright this class is it looks good go we have the class declaration class body we have public and we even have one function in our class this is a pretty sweet-looking class so let's go ahead and use this right now well now I want to talk to you guys about the other part of this tutorial I told you guys I'm going to be talking about classes and objects I already talked to you guys about classes now I want to talk to you guys about objects an object is how you access the stuff inside of your class for example why do you need to make objects at all why can't you just write cool sayings just like this and use it just like that well whenever you're making big computer programs and you have a bunch of different classes and a bunch of different functions and them may have this cool sayings you may have a function that says cool sayings inside Bucky class you may have another function cool sings inside tuna class you may have another function cool sayings inside a class temperature class well how does C++ know what function you want to use well it needs an object and the object basically tells it what class you're working with so in order to create an object it's basically the same as creating a variable you go ahead and you do this you type the name of your class which is Bucky's class and then after this you give your object a name and I'm just going to name my Bucky's object just like that and go ahead and add a semicolon and now this object Bucky's object you use this kind of as the key whenever you want to access the crap inside your class so now instead of just writing on the function name we have to write the object name first like Bucky's object and then in order to access anything inside the class we need to use a dot separator and a dot separator is basically our way of accessing the variables the functions all that stuff so as you can see we'll put the dot separator up and it already knows that we're what we want to do we want to access cool saying just like before just type the name of the function and empty parameters and bam wham thank you ma'am we now have a full working program so let me run this for you real quick to show you guys that it's working make sure I don't have any errors and then I'll talk you guys through it one last time preaching to the choir works perfectly pretty cool huh so anyways people make classes in order to group a similar function so if I had you know a program that just had a bunch of cool sayings I'd have cool sayings cool sayings one cool things too I want to put them all in the same class for now we only have one function because this is just an example so we have a function that we put inside the class and make sure to make it public that means that main can use it as well so we have a class and we made that by making public and through a function inside it pretty cool so now we wanted to actually use that function that's inside the class well we can't just go ahead and write cool saying because if we had a bunch of different classes it wouldn't know which function named cool saying to use so it wouldn't know what class we wanted to use so in order to use that function we needed to make an object of that class so we're saying all right we're making an object called bucky's object and it is from the buckey's class class so now whenever we use buckey's object it knows that we're going to be working with bucky's class so we use buckey's object cool saying and that knows and that's basically our way of telling c++ that we want to use the cool saying function and we want it to come from buckey's class so we use buckey's object so that is why you need objects classes and yadda yadda out of all that stuff so that is your basics of classes and objects and why you need to make objects before you can use the stuff inside your class so I know this is kind of confusing um but this is the basics behind object oriented programming so if you understand this then if you understand this tutorial then the rest of your programming life is going to be a whole lot more simple so watch this tutorial watch it again watch it again until you understand exactly how to make classes and exactly why objects are useful and once you do you're ready to move on to next tutorial so for now thank you guys for watching you guys have no idea how important the information you just learned was so anyways thank you guys for watching don't forget to subscribe if you have any questions about any of this feel free to ask me on the new boston.com slash forum so yeah enough of me talking I'll see you next tutorial what is going on guys it's Bucky and welcome to your 13th C++ tutorial and in this story I'm going to be teaching guys how to use variables in classes but it's a little different than you guys might expect so just stick with me and I'm going to show you guys the wrong way and then we're going to show you guys the proper way to use variables in your classes so before I even get started this tutorial I want to include the string class as one of our files because we're going to be working with strings in this tutorial and if you can't remember a string is just basically another word for text so whenever we were outputting things like hey now brown cow this text is just another word for a string so that's what a string is to give you guys a quick little background on that so go ahead and include the string class right under your iostream right above your namespace and now like I said before I show you guys the proper way to use variables I want to show you guys the wrong way because this is a common mistake that a lot of beginners do so you go ahead and you added your access modifier public and say you wanted to make a name variable low name is of course a string so go ahead and make a variable called name and set equal to the type string this is good to go I mean so now we have a variable in our Bucky class called name so again if you remember from les Sorel in order to use the things in that class you first need to create an object so in order to create an object you type the class name and then the name of your object I'm going to name mine Bo which does not stand for body odor stands for Bucky's object so then we have an object named Bo and with that Bo object we can access variables by using the dot separator and just the name of your variable so then once we have this variable name from the Bucky's class we can go ahead and see it equal to any name we want like Bucky roberts and then this variable right here is equal to Bucky Roberts so then whenever we try to print it out Bo dot name it just goes ahead and it prints out Bucky Roberts on the screen so you're saying all right Bucky that seemed to work pretty darn good to me so why did you say that that was an proper way to do stuff well I don't want to get into too much detail but basically I want to stress this making class variables public is generally not good programming practice I don't want to get into like software engineering but basically whenever you make your variables public it makes your programs really easy to mess up so typically what people like to do is make their variables private and again there are some exceptions but typically you want to make all your variables in your class private so you're saying all right I remember from less storia you told me that whenever I make variables private I can't access in them in main so whenever you try to run this program right here we get an error saying all right this is just going to cause me a bunch of headaches what am I supposed to do well if we remember what I said I said nothing outside your class can access these variables so we need to build a public function inside your class to have access to those variables so that is what we need to do so let's go ahead and delete all this and we already made our variable private so now let's go ahead and make public functions to access them because remember if we make a public function to access that variable we can use those public functions outside our class in our main so in order to do that just go ahead and write public and now everything you type under here is going to be public so we want to add two functions the first one is just going to be first of all we're going to want to do two things to this variable name we want to be able to change it and then that means set it like set equal to Bucky set equal to Tom set equal to Jessica so we want to be able to set the name and our second function is just going to get the name we want to return the value Bucky we want to return the value Tom just go whatever so we have two functions one to set the variable and want to get the variable so in order to set the variable just go ahead and set equal to void because it's not returning anything we're just changing the variable and what people typically do is write set and then your variable name after that and after this we're going to go ahead and use this string and we're going to call X because we're going to be passing in a string such as Bucky Roberts Jessica Thompson Tommy and that variable is going to be equal to the value X so whenever we set a name we want to change it all we need to do is set equal to the variable X and then it sets equal to whatever value we pass in for example if we say set named Bucky it's going to treat Bucky is X and now our named variable is going to be equal Bucky simple enough so that is called our setter method or excuse me setter function a method is actually if I say method and I actually mean to say function just remember that I uh I've been teaching like 80 different computer programming languages and in some languages they call method a function and vice versa so I might get it mixed up but trust me a method and function is just the same thing so anyways with that little background I now want to say this we already built our setter function how to change that name variable well now we want Bo to a function to access it and remember since we want that name in return we go ahead and type string because the name is of course a string a bunch of text so what people typically do here is instead of set they write get because they just want to get the name so go ahead and write get name it's not going to take any parameters and in the body this is probably the easiest thing you're ever going to do all you do is return the variable so check it out we don't have direct access to this variable so we have to go through functions in order to change this variable we go ahead and we use this function in order just to get the value of the variable we go ahead and we use this function so now instead of directly accessing this variable we can do it through public functions so again like I said the only thing that have the only thing that has access to these private variables are other things inside this class so if we make those functions public then we can access that variable kind of like cheating you know so in order to do this again in order to use those functions we again need an object so Bucky's class make another Bo object and now under this if I scroll up we can go ahead and Bo we can use the functions from that class by using the object name and then the dot separator and then we'll just go ahead and the first thing we want to do is set a value to that so go ahead and let me just copy this paste it right here and we'll set the name equal to something stupid like arm sir Bucky Wallis if you guys know where the name Sir William Wallace comes from then leave me a comment below congratulations so now this name variable is equal to the name sir Bucky Wallis so instead of accessing it directly you can see that we went through a function that was public to do so so now what we can do is we can just you know print it out or something stupid so see out and in order to print it out we just can't go ahead and write Bo dot name because we don't have access to that variable what we need to do is we need to go through the function get name just like that and now what this function does is it returns the name it's basically a way to make a private a public simple as that so now when we go ahead and print it out building around this as long as I don't have any errors and I don't check it out sir Bucky Wallis so let me guys let me talk you through this one more time what we did is we wanted to access this private name variable well we couldn't access it directly or else it will give us an error so what we need to do is we needed to build public functions one to change the name and one to get the name so then later on in our program whenever we wanted to use those function we went ahead and we created an object and then remember whenever you want to use anything inside your class right the object dot separator function object separator function and then we ran our program and it worked pretty darn good so that is the bad way to use variables and also the proper way to use variables again you can put these variables is public but it's just bad programming practice and bad software engineering you're never going to get a job as computer engineer if you make your variables public so thank you guys for watching this tutorial if you have any questions check out my website the new boston it's pretty sweet website I definitely want to check it out so I am going to go get a drink because I've cottonmouth now and you guys study this story and I'll see in the next video well is up guys welcome to your 14th C++ tutorial and in this story I'm going to be going over constructors what they are and why they are useful so first of all I want to tell you guys what a constructor is a constructor is a function that gets called automatically as soon as you create an object so before what we could do is we could create an object and use that object to call functions from our class well now as soon as we create this object it's going to call a funk funk ssin code constructor we don't need to explicitly use that object to call a function it's going to do automatically so you're saying alright Bucky you talk to talk time to walk the walk show me an example well creating a constructor is incredibly simple to do so it's basically the same as creating a function with a couple weird rules first of all I need to tell you guys this constructors never have a return type so you don't need to type int or void or string or anything like that the only thing you need to do is type the constructor name and the constructor name is always the same as the class name the exact same so let's go ahead and copy this and paste it right here and that's how your C++ program knows that it's a constructor because once it comes across a function with the same name it knows that that is the constructor so let's go ahead and we'll add no parameters and in the body what do we want to happen as soon as we create this object we didn't have just you know maybe it will print something out on the screen like this will get printed automatically pretty cool huh so now we have constructor that's going to get called automatically as soon as you create an object interesting all right you keep saying that but what exactly does that mean well say we have an object from Bucky class named Bo well before we would have to write Bo yadda yadda yadda whatever we want to use from it but now as soon as we create this object this constructor is going to get called so let's go ahead build and run this and see this will get printed on Mac app will blah blah blah automatically so you could see that before we needed to use that object to call functions but this is a special function called a constructor that gets called automatically as soon as you create that object so you're saying all right that's pretty cool and interesting but why what didn't I just you know print this out on the screen or something else what's the use of a constructor why would you even want things to happen automatically well typically people don't print things out in their constructors actually if you see anyone printing something out in their constructor then they're idiots and you should slap them inside ahead because constructors the main reason that people make constructors are to give variables an initial value so for example this class has a variable called name but it might have another variable called age height weight favorite color favorite sports theme have all these variables so as soon as you create an object from that class you might want to assign a bunch of values to these variables right now so in order to do that here is what you do whenever you want to take a value and assign it to a variable you need to add a parameter in your constructor so let's go ahead and assign a value to this name right here and in order to do that we need to pass in string and just name it Z or something so now what we can do is we're going to be passing it in a string to be setting it equal to name well we already have a function that does that called set name so in order to do that just go ahead and call set name with the parameter of Z so now later on whenever we want to use our constructor our constructor can take a parameter as well and for our parameter let's just go ahead and write something like lucky bucky roberts and now what's going to happen is this as soon as we create this object it's going to call a constructor with a parameter lucky bucky roberts so it's going to go up see if it has a constructor oh I do and as my parameter I need a string and for a string we give it lucky bucky roberts so anytime has saw z it plugged in lucky bucky Reppert so it says all right your constructor you told me to set the name equal to lucky lucky Roberts so it basically set the name equal to lucky bug you're Robert so pretty much lucky Bucky Roberts got passed into Z which got passed in X which got passed in the name so that's why our name was lucky Bucky Robert so now that our name is lucky bug you're Everts that gets kind of repetitive saying that but anyways we can just go ahead and you know print it out on the screen or something so of course to access anything in our class use the object and of course the get name just like that function so let's go ahead and build and around this and we have int main we got a problem here hold on one second we find it oh I see what the heck how in the world did I do that for some reason I must actually hit paste or something but I copy the word name outside my class I just wrote the word name randomly in the middle of my program so remembering not to put words randomly in am over your program or else it won't run so now let's go ahead and build and run this and check it out lucky lucky Roberts so that is the basics of a constructor how they work and also how you can add a parameter to your constructor and basically the only times you wouldn't want to add parameters to your instructors is whenever you're taking those variables that are inside your class and you want to set them equal to values initially so that is basically why a constructor is useful whenever you have a bunch of variables in your class and you wanted to set them equal to values initially on that is how you can do that so here's that example and you just printed it our name so simple enough so aside from this I guess I have time to show you this one thing you might be thinking all right so I have an object from this Bucky class named Bo and its name is equal to lucky Bucky Robert so does that mean later on if I were to create another object from the Bucky class name like Bo too and I set this name equal to armed what's even dumber than lucky Bucky Roberts um Sally Mick salad that's that's what's on my mind right now so does that mean that I'm going to overwrite this one well let's go ahead and print out armed bo2 dot get name just like this so let's go ahead and print it out and see what we get lucky Bucky Robertson Sally Mix Aled so why wanna stress is this whenever you create an object from a class each object has its own set of variables so this object Bo name is lucky Bucky Roberts this object is named Sally Mix Aled even though they're from the same class it's not like changing the same variable so even though we set this BL to equal to Sally mixed salad it didn't overwrite this they're just from the same template pretty much so anyways what I wanted to stress is that you can create multiple objects from the same class and they don't overwrite each other they're just a sign they're they're assigned they're each set variables am I saying that right they're each assigned a set of variables so yeah I just wanted to stress that before you get in to objects in classes more and you get confused so anyways that's just a little side note stick with constructors and then once you're good with constructors you're ready to move on to my next tutorial but for now thank you guys for watching and remember don't stick words into randomly middle of your program and yeah I guess I'll see you next video what is going on guys is Bucky and welcome to your 15th C++ tutorial and in this tutorial I'm going to teach you guys how to separate your classes and actually add them in different files so what programmers usually like to do is they like to separate their classes into separate files because it just makes it easier to work with and manage and edit later on so once we have like a huge program with 100 classes we don't want all of those classes in the same text file or l so just get way too huge so what they like to do is separate it and it makes it easier to work on especially if you're working with a couple people maybe one person could work on each file at a time so anyways enough of me talking let me show you guys how to do it so we have a basic program right here and we decided that it's time to add a new class well in order to do that go ahead and press file new class and then we have a new pop-up box that pops up the first thing we have to do is name our class and I'm just going to name mine burrito or something like that and by default a couple things are checked and I don't like to have them checked there's something called a destructor and we're not going to deal with any of that yet so uncheck virtual destructor and also has the structure and another thing I like to do is I like to keep all my class files in the same directory as my main file so by default I think this is unchecked and what you want to do is check it in that way all of your files are going to be in the same directory or in the same folder as your main CPP file so once all your settings look the same as mine go ahead and press create and what it's going to do I'm just go ahead and press yes yes to that stuff and what it's going to do is it's going to create a couple files for you and you're saying RA Bucky what the heck is all this I thought I was just going to give me a blank file I was going to put my class in it and I was going to be good to go well what we need to do is we create our class a little bit different than we were creating in the last couple tutorials we're going to be separating it in the two files so by default codeblocks automatically created pretty much a template of the two files that we need one is a dot H and one is a dot CPP the dot H is called the header file and the dot CPP is called the C++ source file and this is we're going to be writing the code so first of all let me explain you guys what the header file is the header file is where we're going to be putting all of our classes function prototypes and variable declarations so remember before I said that whenever you made a function you could go ahead and prototype it above it main well we're going to be putting all those prototypes in the header you'll see later on and aside from that this dot CPP file is where we're going to be actually building the functions themselves so this is pretty much where all the titles go and this is where all the bodies go basically it's a little more in-depth than that but that's a real basic summary so the first thing that I like to do is get rid of this private and protected because we don't have any of those yet and another thing that I like to do first off is see this dot CPP file or CIN all right how come you needed this using namespace and include in this CPP but you don't end this CPP well actually you do so go ahead and copy that and paste it right in there so again both of these dot CPP should have the same things include iostream and using main page namespace STD so once you have this paste it in your new burrito CPP you're going to be good to go another thing that you're going to see is this class has already built our constructor for us remember in the last tutorial I thought you guys had boat constructors what they are pretty much functions that get called automatically well as you can see this already builds the function prototype and starts building the function body for us so um by default it just has a comment in it and I don't even know if I told you guys what comments are but they're pretty much just little notes that you could write to yourself I'm have no effect on the program so let's go ahead and delete this and before I start writing something in this function I want to talk to you guys about this the last thing that might confuse guys is the colon : what this double colon is is it's called the binary scope resolution operator so just remember that for your test so that's the technical term but what the point of it is is it's basically saying that this function which is called burrito because it's a constructor excuse me because it's a constructor is a member of the class burrito so usually you're going to have this second one be a different name in this first one state burrito but anyways it's basically saying that this function is a member of this class and you use that the two colons right there if you didn't include those colons then it wouldn't know what class this burrito was supposed to belong to so it will give you a bunch of errors but now whenever you're making functions make sure you have the class before it separated by two colons again it's kind of weird seeing the first but you'll get used to it so aside from that let's just go ahead and add something to the constructor so remember a constructor gets called automatically as soon as we create the object so if we go ahead and just go ahead and type like I am a banana or something like that something incredibly stupid so now let's go ahead and write end line and now whenever we create an object from this class it's going to print out I am a banana spelt it wrong but hey who cares so before I go ahead and run this program I want to talk to you guys about one more thing you sent all right Bucky I understand how to do this in it's not like I made C++ or anything but just out of curiosity why do you have to separate the dot H in dot CPP file why didn't the users who ever made C++ just let you make it all in one file well the reason behind that is this whenever you're going to you know give these functions to your friends to use or maybe you're working on it with a team of programmers or maybe you're just distributing this for sale on the internet well you're going to want to compile this right here and change this all in ones and zeros and where you're going to be giving the other programmers is this and raising you only give them basically the prototypes or the titles of the function is saying alright I already built all these functions they work perfectly you don't need to change it all you need to do is to use the functions themselves so again whenever you're distributing this this is going to get compiled and the programmers are going to have access to your functions but they aren't going to be able to change the function bodies themselves so anyways that's a nice little background you didn't really need to know that for this story of just a nice you know a little tidbit of information so that's why you split them up so the last thing that you need to do is this in order to use objects from different classes in our main CPP we need to include the headers so go ahead and just like your burrito dot CPP included the header we need to include the header right here as well so now that we included the header we can use objects from that class so let's get rid of this see out hello world because we don't need it so now arm now that we have the constructor doing something printing out I and banana we can go ahead and build an object in order to build object we just go ahead and type the class name and some object like Bo and it should be good to go so let's go ahead and build and run this and see what happens I am a banana simple enough so to recap one last time in order to make a new class you go to file new class you name your class and make sure you check to have the header which is this and the implementation file in the same directory as this so now what it did is it created all these files for us automatically the only thing we needed to do is make sure that all of these includes and all of these includes were the same and basically whenever we wanted to use this class and our main CPP we needed to include the header and what this header did is it basically included the whole class and then we were able to use all the functions variables and all the stuff from that class so I know this is a little weird at first because we're just looking at real these small examples and they aren't really useful don't really tie together to make a full computer program but later on once we are building a full computer program you'll begin to see why classes are useful why a header is super beneficial and why you actually do want your function bodies in a separate file so again these really small examples might be hard to see but I just want to break it down easy for you guys so you understand the basics before we dive into something a lot bigger so for now thank you guys for watching don't forget to subscribe and I'll see you guys in the next video what is going on guys welcome back to your sixteenth C++ tutorial and in this lesson I want to talk to you guys about something called the if statement now the if statement is basically a simple way to have your computer program make a very simple decision so before when we were programming we built simple programs and it pretty much just ran line after line after line of code without question so that's nice and all but sometimes you want to have your computer program make a simple choice for example you might have some code that you only want to run sometimes and you're saying all right why would I even put it in there if I only want to run it sometimes well for example if you're making a website and you had a message on there that said hello Bucky well you would only want to show that message whenever I logged in you wouldn't want to show it whenever a guy named Tommy loggin or a girl named Jessica logged in so you would say if the user is Bucky then say hello Bucky so you can see that unlike before when you just built a program in your granite from top to bottom now we have different routes different choices that our computer program can make and the basic basic decision that each computer can make is made using the if statement so the syntax for the if statement is incredibly simple you go ahead and type the keyword if and in between parentheses right after you're going to give it a test now go ahead and add curly brackets and if that test is true then it's going to run the code whatever you put in here if it's not true then it's not going to run the code so you're going to say all right um the test is is the user Bucky and the code would be say hello Bucky on the screen or something like that so that's basic example but of course that isn't real code so let's go ahead and make a real program that actually works so the basic what people typically do is they have a variable first of all so let's go ahead make int X and set it equal to 10 so now we have a variable equal to 10 they might want to test this to see um is this variable equal to 10 so go ahead and say if X and now in order to make these simple tests we use something called comparison operators and when you're testing numbers there are six different ways you can compare numbers I know you think is equal or not equal but there's a lot more first of all you can test is X equal to 10 is X not equal to 10 is X less than 10 greater than 10 less than or equal to or greater than or equal to let's go ahead and test it besides something other than 10 so we know X is equal to 10 if we want to test if it's the same as 10 we go ahead and write equal equal 10 and you're saying all right first of all slow down this doesn't make sense why would you not just write if x equals 10 because that makes sense well the single equal sign is they already reserved that for setting a value equal to the variable so if you did this right here it would think that you're trying to set X equal to 10 and your program is not going to work right so that's why whenever you're comparing a variable and value you need that double equal sign so this means all right test if X is equal to 10 and if it is let's just go ahead and give something stupid C out um OMG IM pritty that means pregnant and ghetto talk so let's go ahead and NL and let's go ahead and run this and see what happens build and run and on the screen that says OMG I am Bragi and why did it do this because we had a variable X and it was equal to 10 and then we said all right if X is equal to 10 then go ahead and print this out on the screen and it was so print it out but if you had something like if X is equal to you know 87 now we try and build and run it you see that our computer program didn't print it out because 10 is not equal to 87 so you're saying all right I know how to test whether a value is equal to a variable but what if I want to test if they're not equal I want to make sure that these values are not equal well the sign for that is a explanation point equal sign this means all right if X is not equal to 87 print this out and it's going to print it out because it's 10 equal to 87 no that doesn't even make sense so it's going to go ahead and print that out so that's why we get oMG I am per Iggy so aside from that let me go over the basics less-than and greater-than if X is less than 87 is 10 less than 87 yes and by the way whenever we have a test and that test is true we say true whenever the test is wrong we say false so it's 10 less than 87 yes 10 is less than 87 so we call this test true and it's since it's true it goes ahead and prints it out oMG I am praying now let's go ahead and be like is 10 greater than 87 No 10 is not greater than 87 so that's why it didn't print it out right there so aside from that there are two other simple ones I want to go over with you guys there is less than or equal to so if you add something like is 10 less than 10 and you just had a basic less time then you try to run it and it wouldn't work because 10 is not less than 10 10 is the same as 10 well what if you want to test the value is less than or equal to another variable well we go ahead and we have our variable 10 is it less than 10 nope or is it equal to 10 yes so this is indeed going to print out oMG I am braggy and of course there is greater than or equal to but I'm not even going to show you example because it's pretty self-explanatory what we have so aside from testing a variable against a value I just want to tell you guys that you can go ahead and test two variables such as 43 so now we're going to say all right is X arm greater than or equal to Y aka is 10 greater than or equal to 43 let's go ahead and go and run that and we see that 10 is not greater and it's not equal to 43 so we can test two variables and we can even test two numbers like is five greater or equal to three and we go ahead and run that and we print out oMG I am pretty but this testing two values is the least common thing people I don't want to say always but I've never seen it where people had two values in here it's either one variable or two variables if we go ahead and we just had this code right here then it wouldn't make sense just to forget this whole if statement just like that unless you don't know how to compare numbers then you would have a problem then you shouldn't be watching this story but for now I just wanted to talk to you guys about the if statement and how we can use it to make a basic decision again technical terms whenever your test is positive we call that a true test whenever your test is negative and it doesn't make sense we call that false so the code inside the if block is only going to run when your test is true as you just saw and again we have two equal signs for equals explanation point equals means not equals greater than less than greater than equal to less than or equal to so now you are pro with the if statement so thank you guys for watching don't forget to subscribe and yeah see you next story what is going on guys welcome back to your 17th C++ tutorial and in this tutorial I'm going to be covering something called the if-else statement now let's go ahead and first I want to build a basic if statement because an FL statement is pretty much like an enhanced if statement so let's go ahead and use the knowledge or the information that we learned in the last tutorial and build on it so let's go ahead and make a simple program we have a variable called age and go ahead and set it equal to whatever your ages now go ahead and make a basic if statement now if you remember from the left story all an if statement does is it runs a simple test if that test is true it runs a bit of code if that test is false it doesn't do anything so let's go ahead and test age say if age is greater than 60 let's go ahead and say um C out Wow you are old so if the user is over 60 let's go ahead and say you are old and now let's go ahead and end that line run this program and see what we get we get nothing and that is because I'm 24 so this program does nothing but you build this program you show it to your boss and you're like hey where's my raise in there like wow this program is impressive in all however wouldn't it be nice if we could give a message to the user no matter how old they are what if instead of skipping this if the test is false let's give them all an alternative message like if anyone's over 60 we're going to tell them they're old if anyone is under 60 we're going to tell them hey get a job so saying alright um I suppose I could put another if statement and then Ray age is less than 60 but you know what that isn't the best way to do things I'm going to show you guys something called the if-else statement so the if statement basically ran a simple test and if that test is true it ran this bit of code and if it was false it did nothing it skipped it but now we want to say all right else if the test is false then we want to run this bit of code so either way it's to run a bit of code either way if it's true it's going to run this bit of code let me just go ahead and copy that if it's false it's going to run this bit of code but let's not put while you're old for either one if they're under 60 let's go ahead and write you are young get a job so now when we go ahead and run our program unlike before when it says our right since this test isn't true I'm just going to skip it it says all right this tests is it true so what am I supposed to do it's false well I'm supposed to do the else so let's go ahead and nothing be talking run it and it says you are young get a job and of course if the user is like 87 we run the program and they say wow you are old so now you can see instead of just having a basic if statement where it was either run a bit of code or do nothing we now have the option of something happens for true and something happens for false so now either way your computer program is going to do something so that is the basics of an if-else statement so now that you guys know that let me go even deeper I said that you can go ahead and run a line of code inside the if statement well you can also run multiple lines of code just by putting them under each other so if we go ahead and we copy this we can go ahead and paste it paste it paste it it doesn't matter you can go ahead and run it four times as long as it's in between those braces right there server saying all right what if I wanted to do something like this what if not only I wanted to check if they were over 60 but if they were over 60 I wanted to check if they were over a hundred so let's go ahead and do that so what I want to want to teach you guys now is that inside if statements instead of just running simple lines of code you can also put additional if statements this is called nesting of statements so let's go ahead and say if and remember this code is only going to run if the user is over 60 so now we want to test if the user is over 100 and then we're going to write C out armed why are you still alive I know this is harsh but hey just trying to get the point across so now let's go ahead and go around this bit of code right now so our program is going to say this alright if the age is over 60 which it is I'm going to run this bit of code right here and in this bit of code I'm going to test if the user is over 100 well they're not over 100 but they are over 60 so nothing is going to happen so we're going to run this nothing is going to happen but say our user was 178 pretty old huh well we're going to say all right is your age over 60 yes so now go here is your aive is your age over 100 yes it is so now run this bit of code right here and we're going to go ahead and run it and it's going to say why are you still a lot because come on guys let's face it if you're 178 years old you should be dead just saying so now we get begin to see how we can make complex tests and very complex programs and I know that I it's called nesting and if statement inside another if statement but you can also nest an if-else in here and you can also nest another if in here and you what you can do is you can nest if inside of if inside of if as many times as you want but say you wanted to test if the user was over 10 then over 20 then over 30 then no to 40 and the 50 well there's even a more simple way to do this than nesting a thousand different ifs inside of each other and I'll probably be teaching you that in the upcoming tutorials but for now what I want you guys to take away from this tutorial is instead of a basic if statement where if the test is false then it just skips the code you can now add an else and what this does is it gives it an alternative choice and also a side from that you can also nest if inside other ifs so that way you can basically test two things and if two things are true run a bit of code so as long as you understand those concepts you should be good go so for now thank you guys for watching don't forget to subscribe and yeah if you have any questions send me a message on my website the new Boston calm and I'll be glad to answer them for you so thank you for watching don't forget sub and I will see you next story what is going on guys welcome to your 18th C++ tutorial and in this is rural I'm going to talk to you guys about a while loop and every saying alright Bucky take a step back I don't even know what a loop is and now you're trying to talk to me about special kind of loop alright let me step back a loop is basically in computer programming if you want to take a certain bit of code and run it over and over and over again you can go ahead and you can just type it on like a hundred different lines and no keep running or you can throw it in something called a loop and what a loop does it says alright write this code only one time and I'm going to run it as many times as you want me to so for example instead of say we wanted to print hello on the screen 100 times instead of writing C out hello on a hundred different lines we can only write it on one line and loop it a hundred times so it's a much easier way to make pieces of code around multiple times so let me show you guys an example and by the way now I can talk to you guys about a while loop there are many different types of loops a while loop is pretty much the most basic type of loop in my opinion it's the easiest so that's why I'm showing this to you guys first so let's go ahead and I'll show you guys an example go ahead and make a variable called bacon and set it equal to zero this syntax for a while loop is this we're going to say while and then in the parentheses right after we're going to give it a test just like the if statement we're going to test this bacon is less than or equal to five go ahead and run this bit of code over and over again so let's go ahead and just run C out armed bacon is and then now say the value of bacon and then end line so now if you were go ahead and run this you would say alright run it bacon to zero bacon to zero bacon to zero and you can see that it keeps printing it out over and over by now it probably printed it out like 20,000 times so you're saying all right it's kind of useful I guess but would it be more useful if this loop would end for example if we only wanted to run it 20 times how would we go about doing that well sometimes people do want loops that never end but typically they don't typically you want to only have this code run like five times or ten times or 15 times so how do we control exactly how many times it runs well in order to do that we usually add a line of code like this again what this test is going to do is test is bacon less than or equal to 5 and since the value is 0 right now this test is always going to be true so in order to make this test false in this loop to stop running we need to change the value of bacon at some point so it is equal to 5 or greater than 5 and in order to do that go ahead and make bacon equals bacon plus 1 now each time we run gloop is going to go ahead and do its thing right here and then when it's done it's going to add 1 to the value of bacon so the first time it runs it's going to be 0 and then it's going to add 1 to it so then it's going to be 1 then it's going to be 2 3 4 5 and by the time it gets to 5 it's going to change it to 6 and not run so let me go ahead and show you guys making 0 1 2 3 4 5 so we already know why bacon rain in this case when bacon was equal to 0 it was less than or equal to 5 1 yup - yup 3 4 5 is 5 less than or equal to 5 yep so it printed that out but then whenever it said all right the value of bacon is 5 so I'm going to print out bacon is 5 and then I'm going to add 1 to bacon so now bacon equals 6 all right let's try this loop again is 6 less than or equal to 5 no finally the test is false so I can quit running my dumb loop so that is how you add um again like I said and when okay take a take a breath Bucky you're jumping too fast sometimes people want loops to run forever and when they do you do something like the first example I told you but typically and I want to say like 95% of the time people build loops that they only want to run a certain amount of times for example five times if you only wanted to run at five times or actually it was six in this case you would add something called this line right here and this pretty much just changes the value of bacon so at some point that test has to be false if you wanted to run it 20 times you would go ahead and just change that to 20 and check it out bacon is 1 2 3 4 5 all the way to 20 pretty cool huh so you can change how often your loop runs by a couple things it's starting point it's ending point or how much you increment that value by again you can add 3 to each time if you want and then you get something like this one at 3 2 4 7 10 13 16 19 and when you added 3 to that and it was 22 well 22 is indeed not less than or equal to 20 so that's when it stopped the loop so that is the basics of a while loop again all the while loop does is take a certain bit of code and runs it over and over and over again until the test is false and again like I said at the very beginning of this tutorial there are many different loops that allow you to take a bit of code and run it over and over and over again a while loop is pretty much just the most basic kind so make sure whenever building your while loops not to forget to change that value or loops going to run forever and who wants that so for now thank you guys for watching I'm actually going to go make some bacon right now so you guys sit tight re-watch this story and once you're good once you understand the syntax of how a while loop works you're ready to move on to my next video so again thank you don't forget to subscribe and I'll see in the next video what's going on guys is Bucky and welcome to your 19th C++ tutorial and you know what all these nice little quick examples are fine and dandy but let's go ahead and build a program that is actually somewhat useful a program that you can use and you know maybe your teacher assigned you something or maybe your boss came to you and is like you know what Bucky I want you to make a program that allows the user to enter five different numbers and then I want you to total the numbers for them but you have to use a while loop so we're saying alright no problem so here is how I would go about making this program and by the way this is some nice little programming tips you start with the basics of your program and you do it in little baby steps so first of all I want to make a loop that runs five different times so what I would do is make a loop int X set this variable equal to one this is just going to be the looping variable while X is less than or equal to five let's just go ahead and print out something make sure our loop is working see out X end line so that's going to print out X and you know how I said that in order to add 1 to X each time you go ahead and write x equals x plus 1 well you can do that but let me let you guys in on a little secret if you go ahead and write x plus plus this is the exact same as writing x plus x equals x plus 1 it's just a quicker and easier way to do things and that's actually where the name c++ came from they wanted it to be queue in you know anyway so that's the history c++ it came from an old language called C and they added two little pulse signs to it thought it was cute so anyways that's your history C but what we're worried about is making sure that we have a working loop that runs 5 times so let's go ahead and run this so all right 1 2 3 4 5 our lip is working perfectly we can now move on to next set and by the way this was just a tester line we don't really need that in our program so Centauri our boss told us to make a program so the user can enter 5 for numbers so we already know that the CIN is the way that the user can enter a number but we probably need to store that number in variable so let's go ahead and store that number in a variable number and since we don't know the value yet we can't set that equal to anything yet so what we would do in order to have the user enter a number five times is inside this loop go ahead and write CIN number now our loop is going to run five times and the user is going to enter a number each time before the program quits so what I would do now is test the program again just to make sure it's working all right 43:54 66 2 & 3 enter our programs done so now we see not only do we got a loop that runs five times but we also have the user enter five different numbers so our program is working five and dandy so far service NRA now what's the last thing he said oh yeah he wanted to find a sum of all those numbers and printed it out to the user or something so saying all right now not only a number variable but we need another variable to hold the sum or the total of all those numbers so what I would do is go ahead and put int total and by default their total is going to be zero because they didn't enter any numbers yet that's what we know so now what we can do is this you might be thinking this so just go ahead and set total equal to number but whenever we run this it's not going to work because say they enter ten the first time we're then total is equal to ten okay it's working fine so far but the next time they enter eight and we are expecting 18 well this isn't being added the total total is now being changed to eight so instead of being 18 it's just a so this isn't going to work so what we need to do is do this total equals the old total plus the new number so now what happens is this whenever they enter 10 it's going to be 0 plus 10 total is equal to 10 the next time they enter 8 8 equals number so 10 plus 8 equals the new total of 18 so let's go ahead and once this loop is done running let's go ahead and just give them a nice little print out on the screen on your total is total and might as well end that line why not so let's go ahead and run this program and now let's go ahead and run it and make sure it works so let's go ahead and put 10 enter 8 enter 2 enter 5 enter 5 enter your total is 30 so all right let's go review this one last time it seems that everything is working fine let's just go ahead and make sure well I guess I can cover that up that says end line there now I'm covering it up so basically the first time the first thing we did is we got a loop that worked then we wanted to have the user enter a number and then we did something with that number so what happened is this the first time the user entered a number it was 10 so the total which was zero before is now equal to zero plus 10 so now total equals 10 the next number they entered was 8 so now the new total is 10 plus 8 which was 18 the next number that entered was 2 so 18 plus 2 now total equals 20 next number was 5 now it equals 25 the last one is 5 also now it equals 30 so this is basically saying all right take the new value of total and set it equal to the old value plus the number that they entered and at the end we just said your total is 30 works pretty good so let's go ahead and just to make sure that it's working good let's really test this add some big numbers like this why why do I keep entering the same number each time and so you know okay I'm not going to check this in my head but you guys can go ahead and check that on a calculator and if it works then it means we just built the best calculator on earth so I'm actually going to go ahead and copy this and email this the Microsoft and hopefully they pay me you know just a couple million dollars for it so you go ahead and what I want to stress in this tutorial is this not only this is how you build a basic program to you know it's just an example of why a while loop would be useful but also whenever you're building programs take it in baby steps do the most basic thing first and then once you got networking going to the next step and then one stat work and you can go on to the final step and now we can do something like maybe we can find the average of all these number or maybe we can find the product or the quotient or something stupid so again take your program and baby steps that way you don't try to build a whole program and then at the end when you got ten different errors you're saying all right what went wrong so that is the basics of not only how to be a good programmer but also how to use the while loop in a meaningful way so for now thank you guys for watching um like I said just going to go ahead cut this and paste it to Microsoft and yeah I'll see you in the next tutorial when I'm a millionaire what's going on guys welcome to your 20th tutorial and in this story I'm going to be teaching you guys how to build a Sentinel controlled program now let me explain you guys what that is you remember in the last tutorial where we built that program and we ran a loop five times and each time we allow the user to enter a number well sometimes we're going to want to build programs where we don't know how many times the user wants to enter a number so if you like we're calculating the average grades for kids in your class you know how many kids are in your class if you are calculating the average age of like people in your family you know how many people in your family but if we build a program and we just sold it to everyone in the world everyone's family has a different size every teachers class size is different so we don't know exactly how long to make that loop last so what we do instead is we give a special code and this code is usually something like negative one and we use this because ages in weights and you know number of things cannot be negative one so whenever we answer negative one this is when our program knows to stop and you know make its calculations or do whatever it does so let's go ahead and I'm going to be building a program that we enter the ages of a bunch of people how many we don't know yet but we're going to enter the ages of a bunch of people what our program is going to do is figure out how many people we entered and calculate the average age of all those people so let's go ahead and it's pretty much an age average er if I was to make this program I would name an age average er 5.0 Wi-Fi point no I don't know it's just like five so let's go ahead and we're going to need some variables the first variable we need is some place for the user to enter and store that age each age at a time so they're going to enter someone's age like 32 we're going to store in the variable age after this we need some way to keep track of all those ages a total so if they enter 32 then 32 we want this this sort of total which would be 64 because we're going to be averaging it later on so int just name it like age total and this of course is equal to zero first but it's going to be the total of everyone's age combined and the third thing we need to keep track is how many people did they enter so you take the total over how many people they entered and this gives us the average age so int number of people entered and I don't really like making variables that long because it's easy to make a typo the longer your variable is but it's descriptive for this story so the first thing we want to do is just write a prompt on the screen see out um enter first person's age or negative one to quit so what we're going to be doing is our code is negative one whenever we get the input negative one from the user we know we know that they want to quit the program so let's go ahead and then give them something to enter age so they're going to enter a number and it's going to be stored in the variable age so now we just need to test make sure it's not equal to negative run and we need to loop this program as many times as possible as long as the value is not equal to negative one so as long as age is not equal to negative one go ahead and run this program and at the heart of this program is this we're going to be doing is we're going to be taking that age total and it's going to be a running total of the old age total plus the new value that they entered for age so the first time say they enter six is going to be 0 plus 6 the next time they enter 10 is going to be 6 plus 10 so the total would be 16 so then when we divide it by the number of people which would be 2 their average age is 8 so let's go ahead and now each time this loop runs it means that they entered a new person so let's go ahead and just write number of people entered plus plus because remember plus plus is the same as adding one to it each time so now we said all right our H total is good and the number of people entered is good so now every time we run this loop we want to give them another opportunity to hit negative one or enter someone's age so make another C out and just write something like enter next person's age or negative one to quit so right now they're going to enter negative one or someone's age and let's just go ahead and end that line so now semicolon there we go so now we're going to store that value an age so they're going to keep running this and every time it runs they're going to have a chance to input input an age what this loop is going to do is check and it's going to run the loop over and over and over and over again until the user enters negative one once they enter negative one is going to say all right that's my sign to bail out of this loop and go ahead and make my calculations so for calculations let's first go ahead and make sure our program is going to work properly by saying let's first tell them number of people entered and I know I spelled that wrong big deal who cares and now we just output number of people entered looks good in line and after this what we want to do is we want to find the average age of all those people so C out average h and then we just go ahead and the formula for average age is age total over number number of people entered for example if your h total is a hundred and you enter ten people then the average age would be ten so let's go ahead and run this program first to see if it works see if I forgot any semicolons or anything all right so the program is up and running it looks good so what I like to do whenever I build programs like this is I like to enter values that I already can calculate in my head just to make sure that computer is calculating so let's go ahead and enter a person with the age of 10 the person with the age of 20 and a person with the age of 30 now I know that whenever I average these together 10 20 and 30 well that's 60 so 60 divided by 3 is 20 so I'm going to be expecting 20 and that that way I know that my program is working correctly so let's go ahead and quit by hitting negative 1 and go ahead and hit enter and it says number of people entered 3 which is correct 10 20 and 30 average age of them is 20 because 60 divided by 3 is 20 so that is pretty cool and our program works fine number of people entered it got that right and it calculated their average age right so that's what I like to do before I enter big numbers like 87 68 5 and all those like fives a real big number so anyways how our program work is this what we did is we built three variables well let me just go ahead and skip to the good stuff it says alright enter the first person's age and we went ahead and we entered 10 right here so it says alright is 10 equal to negative 1 nope so let's go ahead and run this right here I'm going to go ahead and store 10 and H total and change the number of people enter it to 1 and now go ahead and give me another age well we went ahead and we enter 20 so now 20 plus 10 our age total is now 30 and our number of people entered was 2 so it said all right give it to we enter 30 so now our age total was 30 plus 30 which is 60 and number of people entered was 3 so then they said are 8 now give me another age or negative 1 to quit we gave it negative 1 to quit so what bailed out of this loop and it went ahead and is make the calculations for this calculation it just printed out the number of people entered which was 3 and 4 this one is said the H total which was 60 divided by the number of people entered which was of course 360 over 3 is of course 20 so again that is called a sentinel control loop because we can run this program in it doesn't matter how many numbers we enter you know we're not limited to 5 or 10 or anything as soon as we hit negative 1 it calculates how many people we entered and their average age so again this is a much more dynamic program in the sense that you're not only limited a certain number but you can disperse this you know maybe a bunch of different types of people and it doesn't matter their sample size any size any amount of people in this program is still going to continue to work fine so that is the beauty of a central control program these are the loops that you're going to be using more often rather than you know a fixed number so get used to it become familiar with it and once you are you're good go so for now that's all I have for you guys in the next tutorial don't know what I'm going to be covering but my throat is dry now so I need to go get a drink water and you need to watch more of my videos or something I don't know so thank you guys for watching don't forget subscribe and I'll see you next time what's going on guys welcome to your 21st C++ tutorial and before I even get started with the story I just want to mention one thing that you guys probably notice already and that is I don't have return 0 at the end of my main and that is because I just found out that well let me say this in the old C++ ways you had to have that return 0 statement but now the new version or whatever whenever you don't include return 0 at the end of your main C++ just assumes you return 0 after the last statement so you know if you go ahead and type your program you can either put it if you're you know old-school programmer or you cannot include it and it would just assume you have return 0 but for the rest of these stories I'm going to exclude it so you know don't forget that it isn't there so anyways let's go ahead and get to the heart of the story and that's assignment operators and increment operators now we already know well let's go ahead and get a variable first set X equal to 10 looks good so we already know we can do something like this X plus equals 10 and this is basically the same as writing x equals x plus 10 so then whenever we let me just go ahead and this line and print it out we go ahead and we get 20 just like that so what it does is it takes to this value adds it to X and sets equal to the new X variable so I already told you guys plus equals is a shortcut I also want to go over all of them so when you see them in program you don't get confused X well let's change this to 5 it's weird if they're the same number so X minus equal 5 equals 10 minus 5 and assigns that to the new value of x so let's go ahead and see that that is 5 now if we go ahead and see multiplies equals what this would do is do 10 times 5 and set it equal to 50 and the last one without getting in the weird stuff is divide equals 5 and this of course is 2 so what this does is basically takes the old value of x it divides it by this value and sets it equal to the new value of x so aside from that there's one more and I rarely use it this way I hate writing in like this and I hate seeing other people rate it like this because it's confusing this is going to be a bad example because ten divided by five is two with no remainder so it will be zero but if we go ahead and throw like three something like this what this does is it takes the old value of X divides it by three and it stores the remainder in one so now X is going to be equal to one right like that so those are all your assignment operators plus minus multiply divide and modulus which is remainder so now whenever you come across them in programming you'll understand what they mean so now what I want to talk to you guys about is those increment operators so let's go ahead and get new value 20 that's a little bit better it's my favorite number so you know how I told you guys that you could do something like this X plus plus and this was the same thing as adding one to X simple enough right not exactly because there are two different versions of this increment operator and I'm going to show you the difference with little differences between both so let's go ahead and see out X n line let's go ahead and run this and take a look at what happens so our initial value of X was equal to 20 and then we ran this line of code and it printed 20 all right and then we ran this line and it was equal to 21 well what the increment operator is doing whenever you write variable with plus plus after it it's going to go ahead and run this line of code and then it's going to add 1 to that variable so runs this line of code X is still 20 then when it gets done running it assigns 21 to X and then it runs this one so that's why it was 20 21 so saying are a simple enough what's the other version the other version is this whenever the increment operator is before the variable like plus plus X instead of X plus plus what happens is you can see whenever you run the program it goes 21 21 so what this does before the variable is it adds one first and then it runs the statement so adds one right here and then runs it so right here the value of X is getting set to 21 and then run it 21 still 21 21 so it's basically if your pluses are before the X it's going to add one before it runs it if your pluses are after the X it's going to run the line of code and then add one to the variable so it you know if you're building a program in you're off by one you know maybe you're running a loop or something and you're always off by one chances are your pluses are on the wrong side either this side or that side so this is a common error and it's actually something that people have a hard concept understanding but just remember where you add your pluses indicate when it's going to add one before or after the statement and if you remember like that it'll be simple enough so now you understand that you don't need a return zero you understand all these scuse me ooh assignment operators that's actually kind of a tongue-twister assignment operators assignment operators just hyman operators got it and now you understand increment operators which is plus plus X and X plus plus oh and one other thing there's also minus minus X and what this does of course is subtracts it and X minus minus but I don't need to show you guys that so just remember those four different increment operators all those assignment operators and you don't need a return zero anymore and you'll be good to go so thank you guys for watching my twenty first tutorial no idea what I'm going to cover in the next tutorial but it's going to be sweet so thank you guys again and I will see you guys later what's going on guys is Bucky and welcome to your 22nd C++ tutorial and in this tutorial I'm going to be talking to you guys about a different kind of loop than the while loop this is called the for loop now if you guys remember a while loop was basically something that took a bit of code and ran it over and over and over again this isn't only for a while loop but all loops do the exact same thing they take a bit of code and they run it over and over and over again the only difference is different loops you have to set them up in different kinds of ways so anyways I already told you guys how to build a while loop simple enough so now let's go ahead and take a take a look at the cindex for a for loop and the first thing you need is the word f o R now after this you add parentheses now inside your parentheses your for loop requires three pieces of information a starting value and ending value and how much do you want to increment it by for example if we started at 10 and we ended at 20 and we wanted increment it by 2 it would be 10 12 14 16 18 20 so let's go ahead and build a simple loop that starts at 1 ends at 10 and it increments by 1 pretty much 1 to 10 counting by ones so the first thing we need is to initialize a variable so int x equals 1 now every piece of information you separate it with a semicolon now after this it's pretty much the same as the test in the while loop how long do you want to let your loop run well let our loop run as long as X is less than 10 so it's going to go from 1 to 9 because remember when it gets 10 10 is not less than 10 so it's going to go 1 2 3 4 5 6 7 8 9 but how does it know to go one at a time instead of two at a time or five at a time well that's that last piece of information that this loop needs X plus plus and if you remember from the last story this means add 1 to X every time um you can also do X plus equals 1 for X plus plus is a lot easier it saves you 1 character and you know only two different characters but anyways I'm rambling enough of me talking so basically the syntax for for-loop is this initialize a variable with a starting value give it an ending value and say how much you want to increment it by each time so now we would just do something like this see I'll print out X on the screen and print it out on a new line every time so let's go ahead and build and run this and see what we get 1 2 3 4 5 6 7 8 9 so we started at 1 and we ran the loop the whole time as long as X was less than 10 so that's why 10 isn't print out because 10 is not less than 10 but all these values are and since we wrote X plus plus it went by 1 each time 1 2 3 4 or 5 kept adding 1 until we got to 9 so now let me go ahead and show you different uh you know what just add some different values so you guys can clearly see instead of 1 let's start at 5 by the way 0 & 1 are going to be your most basic starting points but you know you can use anything you want but people typically stick with 0 or 1 let's go all the way to 50 and let's go ahead and increment it by 5 by writing X plus equals 5 which means add 5 to X each time and assign that to the new value so now if you go ahead and build and run this we go ahead and you have 5 all the way to 45 by 5's and we start at 5 right here well all the way till we were less than 50 and that's why it doesn't print out 50 because 50 is not less than 50 is equal to 50 but 45 and all these values are less than 50 and we told it to add 5 to X each time simple enough so basically starting point ending point how much you wanted to change each time so now those are you know the basic Bucky terms but if you're taking a test I want to give you guys the technical terms this is called initialization where you start off a variable this is called the loop continuation condition basically when you're on the end and this is called the increment so with those three things it has all the information that your loop needs where to start where to end how much to go by so this is a really basic example of the for loop all we did is print out numbers and you didn't really do anything useful except learn the for loop so in the next tutorial I'm going to be showing you guys of an example of why the for loop you know it's basically this I'm going to show you guys the for loop in the cool program and I'm going to show you guys how it's going to be used to do stuff like calculate how much money you can make in the stock market so if you don't know what I'm talking about yet just check out my next tutorial because it's going to be awesome and we're going to be building a super cool program so thank you guys for watching don't forget subscribe and I'll see you guys next video what's going on guys is Bucky and welcome to your twenty-third tutorial and in this tutorial I'm going to be building a simple program and I'm going to be using the for loop and I'm just going to be using it to show you guys that it is actually useful outside of just showing you guys examples so what we're going to be doing is we're going to say we're going to start with $10,000 and we're going to invest in the stock market and we're smart enough to earn 1% each day on our money so it's end of 20 or 30 days how much money did we make so you know it's a little funner program than what we've been programming before it's a little cooler a little break from just basic examples so before I get started I want to mention this in our formula for calculating interest rate we need to use a function called power and that's included in the see math library so make sure you include this before you get started in this tutorial so let's go ahead and get down to it now we're going to be calculating interest rates and stuff like that so we're going to be needing to work with decimal points like 0.01 0.02 for 2% but we already know int so can we use integers when working with decimal points like this no we can't it is for whole numbers only like 98 for 54 it's or whole numbers without a decimal place so in order to use a decimal place we need to have a new type of variable and that's called float float is basically the datatype that allows you to work with decimal places there are a couple different ones but this is one of them one of the most popular ones so let's go ahead and make a variable called a and this is going to be the amount we're trying to figure out how much money did we make the next variable we need is called principle so floats P equals your principal amount in in everyday terms how much money did you invest how much money did you start with well say we just had $10,000 laying around so let's go ahead and start with that I wish I had $10,000 around but hey we can dream can't we so now let's go ahead and say this our last variable is rate so I'm going to set it equal to R and that's how much interest do you want to earn each day and let's say we can earn 1% each day and that's point o 1 if you had 2 percent it would be 0.02 make sure not to put 2 or 1 for this you need point o 1 and or else it's not going to work so let's go ahead and use the for loop to run through each day so what this is going to be doing is looping through each day one by one one two three four five six seven days and each day it's going to give us a dollar amount how much money did we earn that day at one percent so of course the for loop is going to loop through days let's go ahead and make a variable called day in today and we'll start at day one obviously and the next parameter needs is how long do you want to invest your money for so let's say on 20 days so day is less than or equal to 20 days and of course day plus plus because one day at a time we're not skipping any days and we're not taking any vacation time here so now the formula for interest rate exists the amount of money that you earn is equal to the principal amount times and in parentheses put this actually no not yet the principal amount times the power and this is where you put parentheses 1 plus the rate and this is would be let me go ahead and type this out I can't talk and tell you guys financial formulas at the same time the formula for calculating interest rate is this the amount of money you're going to make is equal to your principal investment times 1 plus rate in the rate would be point zero 1 in this case 2 the day exponent so it would be like umm one percent 1.0 one percent to the 20th power so I mean it's a weird formula but that's how you calculate just trust me it works so anyways now what we have to do is just print out on the screen how much money we're going to make so let's give it a nice little print thing arm let's go ahead and print the day first and then just want to give it a nice little spacer here there we go and then we go ahead and write a a is the amount of money that we're making and then go ahead and we'll print this on new line each time so let's go ahead and run it and you'll see what I'm talking about whenever I run it so here is the day to the left one through twenty we start off and at the end of the first day if we invest $10,000 at one percent we earned a hundred dollars at the end of that first day at the end of the ninth day we almost earned eleven thousand dollars if we invested $10,000 and we earned one percent each day for twenty days at the end of your twentieth day you would earn over twelve thousand dollars well you would actually earn two thousand dollars but calculating the money already had in there you would have over twelve thousand dollars that's pretty sweet huh so now you know why everyone wants to get in stock trading because basically by just sitting at your computer and clicking buttons making trades you can earn two thousand dollars in twenty days pretty sweet huh so since you know this is fake money and we're just dreaming let's say that we could we were a genius like Warren Buffett or Bill Gates and we were smart enough to earn 3% each day now let's say we invested this for 30 days so go ahead and let me run this whole mama check this out if you invest in money for 30 days and you earn just three percent on your money each day at the end of 30 days or one month you would over double your money you would have twenty four thousand dollars and more and enough to go out to Taco Bell so that is pretty sweet and this makes me second-guess my career as a computer programmer and kind of makes me want to get in the stock market but by the way before you guys get into the stock market earning 3% a year would be good nowadays earning 3% a day is virtually impossible unless you're like Warren Buffett so anyways there is your tutorial on a useful way to use the for loop in program and also you know some financial advice - the formula for APR so there you go and I hope you guys learned at least something from this thorough and hopefully I didn't get you addicted to the stock market because hey we got more c-plus supposed to learn guys so thank you guys for watching don't forget to subscribe and yeah I'll see you guys later what is going on guys it's Bucky and welcome to your 24th tutorial in C++ and in this story we're going to be covering the do-while loop but you guys probably already knew that because I got a feeling that the title is right above this video and you know what else I do a lot I tell you guys this is probably going to be a short video and I just realized that the time is right under the video so I don't know why I say those things but it's habit I'm going to continue to say those things so get over it so anyways we're going to be covering the do-while loop in this tutorial and if you remember from I don't know however many tutorials those go I talked to you guys about the while loop and the while loop was basically a loop that you had a test and if that test was true then you ran a bit of code inside while the do-while loop is basically the while loop flipped upside down what the do while loop does is it runs the bit of code first and then it runs the test so let's go ahead and let me show it to you guys and you guys will understand better one means let's go ahead and get a counting variable called X and set it equal to one this is our starting point now the syntax for do-while loop is do and then you go ahead and add some code in the body so let's just go ahead and print out X and then after this we need to increment X or else the loop is going to run forever so X plus plus and now after the body immediately after it you write while and then after this you have your test ended with a semicolon a lot of people forget that semicolon because then basic while loop there is no semicolon if it's not in the body so don't forget to put this in my Coleman right here so let's give a simple test like X is less than 10 now go ahead and run this and check it out just like the wild loop it ran the same bit of code print it out X on the screen from 1 all the way to 9 pretty cool huh so we're saying all right a couple of things are kind of weird here first of all why is this loop even useful because it seems like a bad while loop because isn't the point of a loop to run the test first and if the test is true then run a bit of code but if it's false then don't run the bit of code well people use do loop mainly for this reason whenever you have code in here and you need it to run at least one time it's guaranteed to run at least at one time and the reason is this say you have a test that is false like 99 well this test is going to come false as soon as it hits it 99 is not less than 10 99 is a whole lot bigger than 10 so whenever you run this is just going to print out 99 so as you can see it ensures that you run your code at least one time before testing it at all so no matter what this value is it's going to do it one time and then test it so whenever you want to run your code guarantee that it runs at least one time this is what you do so that's the main reason that people use a do-while loop to ensure their code runs at least one time again if you have a basic program and you just want to loop it normally your best bet is to run the while loop or the for loop because those are your basic loops where you test it and then depending on the test you run your program so again this is basically a weird a kind of loop this is probably the most uncock Loup but whenever you come across it I wanted you guys to pick up on it understand what it's doing and why some people prefer it over the wall loop so now that you have knowledge of the do-while loop and you guys know that it's really not that common in programming so you don't want to use it that often you at least know what it does and how I was going to say how it worked well yeah that makes sense and how it works so anyways that's all I have to cover for the do-while loop pretty simple basically a while loop flipped upside down so thank you guys for watching don't forget to subscribe and yep I'll see you in the next video what is going on guys welcome to your 25th C++ tutorial and in this story I'm going to be talking to you guys about a really cool feature of C++ not only C++ this is basically in all computer programming languages but it's called the switch statement in the switch statement in your computer programming career is going to save you a whole lot of time and headaches so let me give you guys an example of when you would use this say you have a variable like age and you want to test the age of the user and you had a bunch of different um like statements you want to print out depending on how old they were so if they were 16 you would say congratulations here's a new car since you can drive now if they are 18 you would say go buy a lottery ticket if they are 21 you would say go buy some beer so you have all these different values that you could apply this same variable so with our knowledge so far we can build a program like this doing this if age equals 16 let's go ahead and type her body and then after this if age equals this yadda yadda if age equals that and then that well all those if statements are getting pretty old so wouldn't it be cool if we could combine this all in kind of a compact statement well it would be cool well unfortunately we can so on with the next tutorial in the next store I'm just kidding we actually can do this and that is through the use of something called a switch statement now in order to use a switch statement here is what you do type the word switch now in parentheses right after that write the variable that you want to test well we want to test the value of age so let go ahead and type age right in there now after this go ahead and add the body to your switch statement now inside your body you're going to give it all the values which you think age is equal to and we're going to be giving it in the form of cases so pretty much we're saying this in case they enter 16 but don't write in case it's only case so in the case of 16 and then write a colon now after this colon you write whatever statements you want your computer program to perform or computer program to perform you're the computer programmer this is computer programming there I got to straighten my brain so encase the value of age equals 16 let's just go ahead and put something stupid out on the screen like see out hey you can drive now and go ahead and end line why not and after this add a keyword that says break now I'm going to be talking about break later on because it's easier if I make the whole program first before I talk about it now after this we can write something like alright what if the case is 18 then what are we going to print out then um see out on the screen arm go buy some lotto tickets because you can do that at 18 now in line and of course after this at that break statement that we don't know what it does yet but we will and let's go ahead and give it one more case why not in the case of 21 the best one um let's go ahead and see out buy me some beer and go ahead and end that line so now you can see through the use of this switch statement it basically saved us the trouble and the time of making a bunch of different if statements so instead of three different assignments foot foot foot three different if statements we only had one switch and we just tested a bunch of different cases so the last thing is default and what default means is if none of these cases were true if they entered a value like two or something like that it ran through all these cases was equal to 16 nope 18 nope 21 nope so what do you want me to perform by default and of course you don't need like default 2 because it doesn't have a value it's just if all of these values failed then what want me to do by default by default we'll just write C out armed sorry you get nothing because 16 18 and 21 that's real bit where the important stuff happens everything else is just the birthday so let's go ahead and end that line and one thing you might notice um whenever we build and run this you're saying our rights sorry you get nothing because you're two but before you go ahead and go and run this why did I add a break at the end of default and what exactly is break well this break keyword right here pretty much means end the switch so we're saying all right why would I want to end it why does it just keep you know going through the rest of stuff well the reason you had break after each case is because of this say you had 16 and you wanted to test it we know that whenever it ran it printed out hey you can drive now and that's because we tested age and age is equal to 16 so in our first case it's say hey this is a match let's go ahead and run this bit of code right here so since we got a match in our first case there's no need to test this one this one and we're know we're not going to run the default because this is the only one we were on a run right here so what break says is break the switch it pretty much saves your program the trouble of having to run through the rest of these cases because it's not going to be useful to run through the rest of them as soon as you found a match so let's go ahead and say we had 18 in there what we would do is it runs it and it prints out go buy some lotto tickets since we have that break in there it did this all right in the case of 16 nope you're 18 in the case of 18 bingo we have a match so let's go ahead and print out go buy some lotto tickets and break out of this loop so no need to test 21 and no need to use the default since we broke out of it we found our match so again what break does is it basically saves you from going through the rest of the loop and why do I not have one at the end the default because by the time we get to the end of default it's at the end of the switch anyway so why would you need to break out of it if you're just going to exit out of it after the default anyways so that is basically a switch statement it basically takes a variable and test the value against each one of its cases 16 18 21 if it isn't any of those values it runs the default now I have three cases in this example but you can have one you can have a thousand you can have a million if you want and yeah that's all so anyways that is how a switch works and that is what break is and I just want to mention one more thing before I let you guys go break I'm using it in this example of a switch but it's a keyword that we're going to be coming across a lot in C++ programming not only with switch so whenever you see it later on whenever we're doing you know just regular loops or something I just want to let you guys know it isn't only limited to the switch statement we can actually use this all throughout C++ so whenever you come across it they'll be like hey isn't it supposed to go around that because we're not so for now thank you guys for watching understand the switch and once you do you're ready to move on to my next video so like I said thank you guys for watching don't forget subscribe and I'll see you guys in the next video what's going on guys is Bucky and welcome to your twenty six tutorial and C++ in this tutorial I'm going to be talking to you guys about something called logical operators now let me go ahead and build a simple program right now say we were the owner of a nightclub and we wanted to calculate whether a person was allowed in or whether they weren't so first we looked at their age and we're going to make sure it's you know over 21 because we don't want to get sued and the next thing we're going to be looking at is how much money they have because we don't want to allow poor people into our you know 5-star nightclub so let's say they need more than $500 so let's go ahead and make this like person has six hundred and fifty dollars so we can test this like this if H is greater than twenty one and if money is greater than what I say five hundred armed where would I just hit insert where the hex might insert key on this keyboard this keyboard is really my stuff now that look about it so it took me like five minutes to find the insert it was actually by my up and down arrows that's weird so anyways now that we had our nice little break we can go ahead and just write something like C out um you are allowed in and make sure you sell it with a nine and you and make sure you spell in ion or else this program just won't work so let's go ahead and run this and see what we get we are allowed in because we indeed are greater than 21 and we have more than $500 so resent are a pretty cool program maybe I'll open up a nightclub now but check this out this can get kind of confusing after a while because this brace goes to this and this goes to this we're pretty easily distinguishable but what if we had five different tests that we need to check what if we had 20 different tests well one little mistake say we had this over here or program still going to run fine but it looks like this goes to this and this goes the main or something who knows where this one goes I mean putting a bunch of if statements inside other if statements is not always the best idea so we have a better way to test two or more things and that's the reviews of something called logical operators and this allows you to make all your tests on a single line so here's what we can do in this case go ahead and make your if statement and then might as well make our C out right now like you are allowed in explanation point with endline and in our if statement go ahead and write your to test like what do you put age is greater than 21 and whenever you join them you use this logical operator and and and now go ahead and write money is greater than 500 now let's go ahead and run this and check it out same results a whole lot less programming so what and and means do this test and do this test if they're both true then run this bit of code and since they both were true it ran this bit of code if one of them must fall say we only had you know four dollars like that well yeah this test is going to be true because we're great entering turn one but this is going to be false because four dollars is not greater than 500 and whenever you run it we are not allowed and check it out and also if both the tests are false like we're only two and oops right or wrong space for that say we're only two years old and we only have four dollars probably from tooth fairy of course we are not going to be allowed in the club not cool but you know we're two year old who needs to go clubbing when they're two anyways so basically a double + sign means this test all these tests and if they're both true then you can run this bit of code but if one of them is false or both of them is false then we don't run it simple enough on and I say and with this test in this test but you can also have an and in another test and even in an in another test and it's just going to run all of your tests and make sure that they're all true so the only way this bit of code is going to run is if all your tests and this is true so if we send alright I understand that logical operator all the tests need to be true in order to run but what if you say this all right I'm on you know not the most professional nightclub owner so I'm going to allow them in if only one of these tests is true if they're over 21 and they're loud and of course or if they have over 500 dollars I'm gonna lie to allow him because you know if 20 year old walks in with like 8 grand I know he's not 21 but I think we should let him in anyways so say we want to do that make sure only one of the tests is true what we do is use a logical operator called the or logical operator and that's if you see above the enter key on your keyboard and hold shift you get these two little things I call them pipes but I think some people call them pipe lines tell you truth I don't know what they're called um it's like a straight line up and down as you can see but that's what little that's what it is and two of them in a row is the or logical operator and what the or logical operator says is this unlike the end where this one and this one had to be true only one of them has to be true and the other one can be false and it still runs the bit of code so check this out we pass this test is true 26 is greater than 21 but we don't have more than $500 so this is going to be false so true and false so we run it and it allows us in even though one of these was false but if both of these were false say we're on the six years old it wouldn't allow sin so anyways what you have to remember is this that and logical operator both the tests have to be true with the or logical operator one of the tests have to be true and another thing if both of the tests are true and/or it's going to run your bit of code so let's say you were you know 64 and you had you know a crapload of money it would run and even though they're both true it would allow you in anyway so with or this one or this one or both of them have to be true and with and this one and this one has to be true and of course you can add another or test and another or test and another or test and when you ran a program like this it's going to run through all of your tests and as long as one of them is true for example this one could be true and all these other ones could be false and it was still around this bit of code an order basically means look for at least one that's true and if it's true run the bit of code so now that I've repeated that about 800 times you guys should understand the difference between an and and or logical operator and when you would want to use one versus the other I guess it depends on what kind of nightclub owner you want to be but for now that's all the code on I'm going to do so thank you guys for watching this tutorial don't know what I'm going to cover in next tutorial but if you click on the next link you can see so thank you guys for watching and I'll see you then what is going on guys it's Bucky and welcome back to your 27th C++ tutorial and this tutorial is actually going to be a pretty fun one because we're going to be talking about random numbers what they are you know a couple functions that are going to help us build a random number generators and I'm actually going to teach you guys how to build a sweet random number generator so before we get into that we need to include a header file so include and the header file is called C STD Li B from the C standard library and we include this because we want to use a function from it called R and not run Rand and what this does is whenever you call this it basically returns to you a random number so let's see let's run it and we got 41 in this case so as you can see whenever we print out R and it pretty much takes a random number and gives it to you sorry saying Wow there you go there's our random number generator perfect well they're actually a couple problems with the rand and we're going to be talking about those later on but for now I want to show you guys how to build a basic random number generator and let's go ahead and just call Rand like 25 times so let's go ahead and make a for loop and go ahead and make an x set equal to 1 and make X is less than 25 and of course X plus plus so now we have a loop that's going to run 25 times or sometime around that so now let's just go ahead and see out umm well let's just go ahead and see out Rand and see what happens and then might as well end that line so it looks so nice and pretty let's go ahead and print it and see what we get okay so it looks like we're getting a huge list of random numbers all right looks pretty good but you know what if I'm going to build a random number generator and I don't want numbers quite this big in tens and thousands and stuff like that say we're building a random number generator to simulate people rolling dice or something well I only want the numbers 1 to 6 so here's a neat little trick where you can get that result set in order to get a certain set of numbers go ahead and take your R and and put modulus 6 what this is going to do is it's going to give you six random numbers it's going to take a big number like 25,000 or something divided by 6 and give you the remainder of that so the remainder whenever you divide by 6 can either be 0 1 2 3 4 or 5 so let's go ahead and take a look at that whenever you divide by 6 you're limited to only the number 0 1 2 3 4 & 5 you can't have 6 as a remainder because anything divided by 6 with 6 remainder it would just be another one so you can say all right well I'm trying to simulate a dice here and they have the numbers 1 through 6 not 0 through 5 so we got 6 numbers but we don't want 0 through 5 we want 1 through 6 so Bucky can you just show me how to take all these numbers and shift them add 1 to them well that is very simple just go ahead and surround your R + 6 and shift put 1 plus now this is going to do is it's going to take a random number divided by 6 and whatever the remainder is which would be 0 through 5 it would add 1 to it so now you're giving 1 to 6 so now you can see that 0 is eliminated and we have 6 now so 1 2 oh let me find it three three four five and six so that is how you build a random number generator using you know a specific result set so remember however many numbers you want you put as a modulus of R and and however many you want to shift to by just add that many to it but let's go ahead and take a little closer look at this random number generator okay let's read these numbers five six five one one five okay they look like you know they're pretty random to me let's go ahead and run it again five six five one one five that seems kind of familiar let's go ahead and run this one more time five six five one one five all right what's going on with our random generator we built this program perfectly which we did so I mean we use a random RA everything is good to go so what's the deal why did it give us the same numbers every time well in order to understand this I need to talk to you guys about computers and random numbers now listen very closely because this is actually very important no computer random number generator is truly random the truth is that computers are not humans computers have to follow a certain algorithm a certain set of instructions a certain pattern so for example whenever you go into a casino and you see those automated slot machines and it looks like people are just spinning and skipping them random numbers well the truth is that it's not actually given them truly random numbers those slot machines even though they're supposed to be random number generator there have to follow a certain aggregate rhythm a certain pattern and you know whenever you're looking at like game shows or whenever you buy electronic and a flash like random lights well those lights are not random either everything in electronics that is supposed to be random is not random it's a computer it has to follow a complex algorithm in a complex pattern now the reason that these are so complex is that's what gives the appearance that it's random to humans we don't understand this algorithm right away only the computer does so whenever we see numbers like this five six five one one five three six those are random numbers to us but the computer it's really just following a big algorithm so we're saying all right so whenever we're building games and stuff we don't want our numbers to be predictable so what can we do in order to change that algorithm in a little bit well let's go ahead and let me include another no I wanted this yet but the rand function right here runs on a very complex algorithm and I don't know what the algorithm is and I don't think many people do but it's basically a large function that computers excuse me that humans aren't meant to understand so what C++ the developers allowed us to do is seed a random number and you use that in a function called s Rand now what this function does is it allows us to pass in a random number any number we want like 67 and now whenever we build it we get different results six two one six one six now let's go ahead and pass another one like 215 and now we get you know four one three one one or whatever so whenever we see it around a number we throw you know any old random number in there and it changes the algorithm so now I don't even know you know what happens when I type in 43 I get truly random numbers so if you're saying all right so let's go ahead and put 43 in there every time and we get four four one five one okay now let's run again four four one five one OMG Bucky what are you doing all you did is you change the algorithm a little bit and you know we didn't really make it a truly random number January we just gave a different algorithm and follow well all right I'll show you guys one last trick in in order to do this we need to include another header fire and and this is called see time and what this does is allows us to access the clock or the time in our computer and now let's go ahead and pass in a function called time and as a parameter of time not tema time go ahead and pass in zero now let's go ahead and run this and see what happens before I explain it okay two five two two okay let's run again four six one for sweet and one more time five four six four six so now we have a random number generator that works perfectly so now let me tell you guys why we know that we can use s R and to change the algorithm a little bit but if we just threw the same number in here every time oh just you know have a different algorithm but with the same results every time so what time zero does is time zero calculates the seconds sense like 1970 or something and what this does is every second this value is changing so now it might be a million seconds now a million and one now a million two people don't have access to how many seconds are you know counting since 1970 so this gives the appearance that this number generator is truly random now so this value is ever changing and that's why every single time we run our program we're going to get a different result so that is how people build random number generators that are is truly random or they're not truly random but there is random as we can make them so again what we did is here's the algorithm all ran does is it runs a complex algorithm s R and allows us to throw a number in there to change the algorithm a little bit and time zero counts the number of seconds and this value is changing every single second so that's why since this value is changing this whole algorithm is changing every single second and that allows us to make a truly random number generator so there you go I hope you guys enjoyed this tutorial thank you guys for watching and don't forget to include your header files because you can't use this program without it and there you go I'll see you guys next time what is going on guys welcome to your 28th C++ tutorial and in this Israel as you can see I'm going to talk to you guys about something called default arguments so of course we're going to be building a function that takes a couple arguments and a default argument is basically exactly what it sounds like you know how we can have a function to like calculate the area of something and then the user would need to enter arguments like length and another value for width well they can either enter the values explicitly or we can have a default value already in that function so let me go ahead and we'll build a really basic function here just to demonstrate this point so let's go ahead and calculate the volume of a just something a box or something and so we have three arguments or three parameters int length and width and int height so we can go ahead and make this function right now and well let's actually go ahead and make this function right now go ahead and copy this and under main make sure you're not in main when you make this go ahead and paste it and calculate the volume in case you don't know it's just length times width times height so now we can go ahead and call this function C out volume and the user can enter three values like four five and five so this should go ahead and print out 100 because four times five is 20 20 times five is 100 so the volume of this box is 100 so alright we have you know just a regular function here with three values or three parameters that it takes and the user goes ahead and passes in those values and it calculates it perfectly but in order to add default arguments or default parameters here's what you do in your function prototype right here instead of just having you know the variable type and a variable you can go ahead and set these equal to something automatically like one what you set them equal to one right now so if a box is one by one by one we can go ahead and assume that well it's basically this if the user doesn't enter any values explicitly then it's going to use those default values of 1 1 and 1 so whenever we call this function without any values check it out it gives us the value of 1 because a box 1 by 1 by 1 has volume of 1 now let's go ahead and say that the user enters a number like 5 okay so the user enters a number like 5 and it gives us the value of 5 but you're saying all right so does that function use that 5 for length width or height well when a user enters one value and you have a function that has three default values the computer is automatically going to assume that you meant 5 equals the first parameter or 5 for length so if you go ahead and run this again we get 5 that's because it's 5 by 1 by 1 so if you go ahead and enter something like 5 & 6 the user is automatically going to excuse me the computer is going to assume that you met 5 for length 6 for width and by default height was one so the only thing you're really overwriting is length in width so it's basically the rules this you can have a function that has default values and by default it's going to use those values unless the user overrides it with values of its own whenever the user does override it with values of its own it's going to pass them in in order of which it would receive them so if it has send one number it's going to replace default value for that number if you pass it in to number it's going to replace the second value for that number right there and if you just pass it in two numbers is going to of course keep that same default value of one for the last one so you get 30 for your value so of course I just want to point out that you can you know go ahead and add three values if you want but you know what's the point of having default values if you're just going to have three parameters you're going to pass in anyways so basically that is how you have a function that uses default arguments in other words default parameters and one other thing that people typically mess up you only have to put the default value in your function prototype right here whenever you create the function in the function body itself down here you don't put the values down here because you already sent all right if I don't explicitly pass in any values I want to use these as defaults so you don't need to re-type it right here so people get this wrong a lot so don't forget to you know just remember that simple rule so now you understand the basics of having default values in your function why they are useful in how you can pass in a different number of functions like six or six and five or six and five and seven and it will all work fine basically whatever you pass in it replaces the rest with the default values so that's all I have for you guys for this tutorial hopefully you understand if you don't just go ahead and ask me one of the questions on my forum the new busting comm slash forum and I will be more than happy to answer it for you guys so thank you guys for watching don't forget subscribe and I'll see you guys in the next tutorial what is going on guys it's Bucky and welcome to your 29th C++ tutorial and in this tutorial I'm going to be talking to you guys about something called scope I can't remember if I talked to you guys about scope already but I need to talk to you guys about it again anyways so anyways I'm gonna be talking to you guys about scope not the mouthwash a little bit different and also something called the unary scope resolution operator but I call it the colon colon because you know whenever we're typing it it's just a colon colon so let's go ahead and first let me build another function aside from main I'm just going to build another function called Bucky and all this is going to do is well we won't even have it do anything yet so right now we have two functions main and Bucky they're both good to go so sometimes people build variables inside a function like in X and set it equal to 10 well let's go ahead and make some interesting variables I'm tired of X so int tuna and set it equal to 69 now let's go ahead and build another variable called tuna and set it equal to 20 well I just want to demonstrate one thing some people would declare variables outside functions and some people declare variables inside functions now it's not just like some people have blue eyes some people have brand eyes there are people nonetheless and it doesn't really matter where I color they have well actually this does matter it's not a personal preference it actually does matter in your computer program where you declare or make your variable whenever you make your variable outside the functions then every single function can access this tuned variable so this function can use it Bucky can use it every function has access to this variable but for example say you only made your variable inside one function so you only made this variable inside main that means that whenever Bucky tried to use the variable tuna it's going to get an error message so check it out it says tuna what the heck is tuna because main functions are basically greedy whenever they create a variable they're the only ones with access to that variable so that's why people typically like to use variables in declare outside all of the functions because whenever you make a variable outside the function then every single function in your program is going to have access to that so say for example main wanted for an Altoona and book you wanted to print out to know well you can go ahead and run this program right now and check it out both programs are going to print out tuna just fine so the reason Bucky didn't print it out and you only saw tuna once was because we didn't call it anywhere but anyways that's what the scope of variables is basically where you create variables depends where you can use them so if you declare a variable in here only main can use it if you make one in here only buck you can use it if you declare outside both the functions can use it but now we come across a little bit of a conundrum and let's go ahead and delete Bucky for the rest of the store oh because he was just an example a dang fine one but a he was an example what if a user did something stupid like this they made a variable called tuna outside main so of course main has access to it but they made another variable called tuna that's inside main as well so main can access that one too so now when you try to print out tuna as a choice do I use this one or do I use this one let's go ahead and print this out and see what happens it chose 20 and why did it do that well computers pretty much take the most recent or most inner variable that they can they say all right here is a variable that I can use but why use that one when I have one right inside my function I'm going to assume that since this one was built right inside my function that that's the one you want me to use so these are called local variables and these are called global variables and when it has the choice it's always going to choose that local variable so you're saying all right let's go ahead and say that I'm building a function just like this and I want to call both of these variables tuna but I actually want to use this variable tuna out here well how do I tell my program that all right I know you have a local variable called tuna but I want you to use this one well in order to do you need to use something called the unary scope resolution operator in other words the : : : : tells your program all right you have two functions called tuna one of them is local and one of them is global whenever you have this : colon before tuna that means use the global tuna in other words use the tuna outside your function so now whenever you run the program check it out it uses that global tuna instead of the local tuna and the reason people actually do this is because when they have variables with the same name of different data types that's when it comes in handy so for example if you had an INT tuna and the double tuna and you ran it it would use the double tuna which is 20 but if you use that colon colon which is called again the unary scope resolution operator if you're taking the test or something then it uses a 69 so I just don't want to show you guys if you're stupid and put in twice people typically write variables with the same name whenever they're using different data types so just wanted to point that out so what to take away from this tutorial whenever you create a variable inside a function you can only use that variable inside the function where you created it you can't use it inside any other function whenever you create a variable outside of function you can use it in any function in your entire program so if we had another function called Buckey and another one called Toni and another one called Jessica we can use this tuna in all of those functions so that's why you can decide whether it makes this outside or inside your function and the last thing I want you guys remember from this story whenever you have two variables with the same name one is local and one is global and you want to use the global variable in your function you need to use this dot dot or colon colon unary resolution operator whatever the heck you want to call it it's two colons before your variable and that tells C++ hey C++ I know I have variable in here but I want to use this one the global variable instead and if you remember these three rules you'll be good to go so that's all I have for you guys for this tutorial again basically a really easy tutorial just a little weird concept that you have to understand so thank you guys for watching don't forget to subscribe and I will see you guys in the next video what is going on guys welcome to your xxx C++ tutorial 30 tutorials that's like a milestone or something and in this tutorial I'm going to be talking to you guys about function overloading what it is why it's useful and when you would use it so let's go ahead and say we wanted to build a function - I don't know maybe we wanted to have the user and put a number and we just wanted to print it out on the screen really stupid function but really simple so let's go ahead and make two variables we'll make an end of your variable a and we'll set this equal to you know 54 and we'll make another flow variable and remember a flow is basically a number with decimal point so we'll use like 32.4 yadda yadda something something stupid so now we have two different types of numbers an integer and a float well we have a function that we are gonna build called print number so let's go ahead and call this function and again we didn't build this yet so for your looking where did print number come from we'll build it in a second so we're going to go ahead and try to use this function for both of these variables print number a and we're going to try and print out B 2 so then we say alright now we're going to go ahead and build this function to print out a number so we go up here it's not going to return anything so we're just going to be void of course it's named print number and then we get to this part right here alright let's go ahead and think for a second if we go ahead and put int X then we're going to allow to pass in an integer so this is going to work but this isn't going to work so I know what I'll do I'll just put flow X well then this is going to allow me to pass in this number but then this number isn't going to work so how do we solve this little puzzle right here well we do this through the use of something called function overloading and function overloading is the idea that in C++ you can build more than one function with the same name in this case we're going to build it be building two functions called print number that take different types of data depending on what you pass in for example we're going to build a print number right here that takes in your value and just go ahead and see out I am printing and integer and then go ahead and print out the integer X and then in that line well that goes ahead and takes care of the integers that the user might enter and now we can build another function with the same name which is print number again if you double click it you'll see the exact same name the only difference is it takes a different type of parameter this one takes a float number instead so now whenever we call this method and it has an integer it's going to use this one and whenever we call this method and by method I mean function I saw sorry I could switch it on and off but I teach too many programming languages to keep it straight so whenever it calls a function with a float it's going to use this one it's smart enough to automatically know what type of data you're passing it in so this one is going to print out C out now I am printing a float which is X and n line so as you can see these functions are basically identical it just runs whatever pretty much whatever type of Daddy pass in it looks for whatever function is appropriate for that type of data and it uses that function so let's go ahead and build and run this and check out what we get at first we pass then an integer 54 so that's why I used this one that took an integer and it said I am printing an integer and after that we pass then in the same function a float which was 32 point four so that's why it chose this one now I am printing a float 32 point 4 so as you can see function overloading solves the problem of having one function so check this out instead of trying to explain our boss that they need to use a bunch of different functions depending on what type of data we can make them happy and say alright anytime you want to use a function just go ahead and use this print number function and put in any number you want this is going to be behind the scenes stuff that they don't have to worry about they don't know that we had to make two different functions just because they were annoying and they couldn't understand that they needed to work with different types of data so we're going to make it really easy for the user through the use of function overloading now whenever the user enters a number like 54 we already have a customized function that is smart enough to realize that they are entering an integer and prints out that value but if someone another user like user B enters a float then we of course can handle that too because our program knows it's smart enough to realize that we're passing it in a float so that's why it chooses this so basically whenever you use a function your computer program is going to do this it's going to look for a function with that name if print number if it has more than one choice then it looks what type of data are you passing it in well if I pass it in a float it's going to look at this one the zips print number take a float nope it takes an integer does this print number take a float yes it does so I'm going to use this one right here so that's why whenever you create a function you need to write the name and also the type of data that you're passing in so then whenever the user tries to use it it knows what function to use so that is basically all function overloading is it's basically making programs that are really simple for the user even though they might take us a little bit of extra coding hey when we want to build software and we want to sell for million dollars we're going to want to make sure that it's easiest for the user to use as possible because I mean when we become a millionaire this extra function is not going to be a real big problem for us so that is how you make million dollars and also that is the basics of function overloading basically many functions with the same name just different data types so thank you guys for watching don't forget to subscribe and I don't know what I'm going to be teaching in the next tutorial but I got a feeling you guys definitely want to check it out so again thank you don't forget sub in I'll see you next video what's going on guys is Bucky and welcome to your 31st tutorial and in this story I'm going to be talking about something that every single computer science student on earth just absolutely hates and that is called recursion now this is a topic that's somewhat confusing but I'm going to try to make it really simple for it you guys so what recursion is is the idea that a function can call itself pretty weird huh so you know how like in main we could call another function called Bucky and Bucky would print something out on the screen well recursion is the idea that Bucky could call Bucky that's interesting so let's go ahead and take a look at this right now say we had a function called Bucky and all it did was print something out on the screen like see out um print out something stupid oMG WTF vbq oh my god WTF BBQ and then it went ahead and it called the function again so now you would say alright well isn't this function gonna go ahead and we're going to run main first and main is going to say okay go ahead and run Bucky and Bucky is going to say okay print this out and then run Bucky okay Bucky print this out and then run Bucky again print this out run Bucky print it out run Bucky and whenever we go ahead and run it we can see that this is a function that basically never ends it prints out oh my god WTF BBQ until check it out watermelon exe my computer just crashed and gave up on this so I'm like alright so what's the point of using recursive functions other than don't use them because you know first of all if you build a recursive function like this your computer's going to crash just like - and it's not the most useful way to go about things so one reason that people use recursive functions is first of all let me mention this whenever you build a truly perfect recursive function you need to have something called a base case now a base case is pretty much an ending point for your function so one example that I'm going to shown you guys is how calculate factorials now if you remember from math class factorials are pretty much when you say five factorial and it's written like this five explanation point this is pretty much the same same as saying 5 times 4 times 3 times 2 times 1 um 7 factorial would be 7 times 6 times 5 times 4 times 3 times 2 times 1 whatever factorial it is is just whatever number times all the way to 1 so then the value of like 5 factorial is 120 the value of 3 factorial is 3 times 2 times 1 which is 6 so let's go ahead and write a program to do that and this is one of the instances where recursion is actually a good idea so let's go ahead and make a function called we'll call it factorial final so int first of all third spell that right int arm factorial finder I think I spelled that right and it's going to take a parameter which is in X can I not spell int today int X and the parameter it takes is what value do we want to find the factorial of so if we passed it in 5 hopefully it would give us 120 if we pass the N 3 it would give us 6 so on and so forth so the first thing we need build is something called a base case without a base case this factorial finder would never end just like Bucky you know how I ran forever until my computer crash this is what this going to do if we don't give a base case so we need to say okay if X is indeed equal to 1 then we want to go ahead and return 1 so whenever you return something remember your function ends and that's the point that we're trying to get to so in order to do this we're going to assume that they're going to be passing in numbers other than 1 so we're going to go ahead and do this else if they pass in the number aside from 1 like 5 or 3 or 20 or something like that go ahead and return the value of x which is you know 5 320 and then go ahead and multiply that by factorial finder X minus 1 so what it's going to do is yeah it's going to call the same function again but it's going to call it with a different value it's going to call it with 1 less than before so if you go ahead and you pass in 5 to this function what it's going to do is say all right I'm going to call 5 times the 4 factorial or factorial 4 I don't even know how to say it I'm not in mathematician but anyways what it's going to do is going to say this I'm going to call 5 factorial 4 well what's the value of that I don't know the value of that is 4 factorial 3 what's the value of that I don't know 3 factorial 2 what's the value of that I don't know 2 factorial 1 what's the value of that I don't know oh wait I do know 1 factorial is 1 so now that it has that bit of information it can go ahead and solve the rest of the questions that it asks you know how I said I don't know I don't know well now it can say all right Bucky 1 factorial is 1 so now I know that 2 factorial is 2 3 factorial 6 4 factorial is 24 and 5 factorial is 120 so that way you can see that whenever we go ahead and run this on factorial finer there we go I didn't feel like printing out the whole thing that way when you print out factorial 505 and let me just go ahead and end that line and we run this program it says 120 yeah it was 120 but there is a lot of stuff going on behind the scenes that the user didn't have to see what it did is said all right it ran this function like 5 different times searching for 5 factorial and then it caught it again searching for 4 factorial then did again searching for 3 2 and finally when it got to 1 it could answer all the rest of those questions so this is how you can use recursive functions in a useful way again our recursive function is just using the function inside the function body itself whenever you do this you need to have a base case you need to have an ending point that actually answers that question so in this case whenever they got to one it could solve the rest of it could of its questions because if we didn't have that base case like before when we printed out oMG WTF BBQ it would just run forever and ever and ever without an end so that's why you need to give it a base case in other words a point to get to where if it solves that question then all the rest of the questions can be solved so again you guys can probably see why people hate recursive functions but why sometimes you actually need it because there's a lot of stuff going on behind the scenes that we don't get look at but we just have to you know assume in theory that this is going to work so it's a little bit different than regular programming in the fact that you don't explicitly call a function like this that a function is going to call a function for you however many times it needs to so there's a lot of theoretical programming that you need to think of and a lot of different things that can go wrong with recursive functions so that's why I wanted to you know show you guys a quick example of the bad way to use recursive functions in the useful way to use recursive functions but now that I tell you guys at soryo we can finally you know get over cursor functions I you will be happy to know that I don't use recursive functions a lot in programming and we're probably going to be you know done dealing with them for a while but you know it was a topic that we definitely couldn't skip and now they watch this tutorial I'm glad I taught it to you guys so thank you guys for watching don't forget to subscribe and don't forget to put a base case in your recursive functions or else your guys's computer is going to crash so thank you guys don't forget subscribe and I'll see you next video what is going on guys welcome to your thirty-second C++ tutorial and in this tutorial I am super excited because I'm going to begin talking to you guys about something called an array so an array is basically one of my favorite parts of C++ because an array is basically a variable that can store multiple values and you can do a bunch of cool things with them and like I said it's one of my favorite parts dealing with C++ so let's go ahead and get started like I said an array is basically a lot like a variable but instead of just storing one value like 8 or 20 or you know 87 it can store multiple values so you're saying alright that's kind of weird but let me go ahead and show you guys how to make one in order to make an array you first write what data type you're working with let's go ahead and make a simple integer array next just like a variable you type something you want to call it I'm going to call my array Bucky because it's pretty cool name and now right after this with no space in square brackets you go ahead and you're right how many numbers in this case how many integers you want to store in your array so let's go ahead and say 5 so what the compiler is going to do now is it's going to create an array that can store 5 integers so whenever you run this your compiler is going to set aside some space to hold 5 integers so we're saying all right so now 1 array can hold 5 different integers pretty cool huh so here is how well there are a lot of different ways you can create an array but they're probably the most basic and easiest to understand is called an array initialize your list and an array initializer list is basically just a list of numbers and you have to put it in between these squiggly brackets I don't know the technical name for them but they're above the square brackets on your keyboard and in between it you write a comma-separated list of 5 numbers so let's go ahead and print out like um 66 75 2 243 and 99 and that is basically all it is to create an array so we went ahead and we created it array called Bucky and Bucky was able to hold five integers and whenever we gave it its 5 integers we had to put it inside something called an array initializer list so we have 566 75 243 999 so now whenever we want to use those values you're saying RA say I wanted to print out one of these values like two or something so let's go ahead and see out on Bucky okay well I can't do that because if I just save the array name it doesn't know exactly what value I'm talking about here so in order to let C++ know what value you want to use from that array we have to use something called the array index so let me tell you guys this first when I said an array is made up of a bunch of different values the technical term whenever you're working with array is called elements and all they are is values but you know we have to be professional here so we're going to call them array elements so 66 is one element seventy-five is one element two is an element so on and so forth so whenever we want to index a specific element in our array we go ahead and write the index number inside our square brackets so you might be thinking all right the index number for this one is 1 this one is 2 and this one is 3 so let's go ahead and try to print out Buckey 3 and see what happens let's go ahead and end that line and we should be expecting 2 right here so let's print it out and check it out 43 what the heck I thought it was going to be 2 okay so 43 is the fourth one not the third one so what's going on Bucky well the reason that I printed out 43 is because whenever we're dealing with computers I don't know if you guys know a lot about binary and zeros and ones but you know how people start counting at 1 1 2 3 4 5 6 7 8 9 10 I learned how to get to 10 well computer they start counting everything with a zero so whenever we create our array this first element even though it would be number one to us to the computer it's actually element zero so let's go ahead and print out Bucky zero and as you can see whenever we run this we get the number 66 so whenever we are referencing indexes or excusing the elements in our array we have to remember that our array starts counting is 0 so 0 1 2 so this is actually the two index so let's go ahead and print out Bucky - and now we go ahead and we get to right there so again the basic things I want you guys to remember is this an array is basically a variable that can store multiple values the easiest way to create an array is this right the data type right your array name and then right however many elements you want your array to hold and we stored five integers in this case so that's why we passed five integers in in something called an array initializer list so basically whenever we create Bucky five we're telling our computer our right Bucky is going to be holding five different values so compiler go ahead and set aside some space in our memory to hold five integers so that's what it did whenever it created this line and aside from that I want you guys to notice this each value in the array I say value sometimes but technically they're called an array element and in order to reference one of those elements we use something called an array index and the first element in every array is index zero so if you wanted to print out 99 it would be zero one two three four so Bucky four whenever you're around this program is 99 pretty cool huh so that's basically the most simple way I can explain array see you guys again I said that one way to create an array was to use an array initialize your list and the next tutorial I'm going to show you guys a different way to create an array and it's a lot cooler way so if you don't quite understand arrays yet and quite understand why they would be useful then just stick around and I trust me what I say I trust me of course I trust myself and trust me you guys will in the upcoming story so again thank you guys so much for watching and I'll see you in the next tutorial alright guys welcome to your 33rd C++ tutorial and in this story I'm going to teach you guys an easier and quicker way to create an array and that's through the use of loops so in the last tutorial I tell you guys what an array was and also that we can create an array using something called an array initializer list and this is actually pretty useful when you're dealing with smaller arrays but whenever we're working with bigger arrays say that store a hundred elements or a thousand elements we're going to need a quicker way to create that array instead of making a huge long list so let me go ahead and show you guys exactly how to do that so in our very first line we're going to declare our array we aren't going to set it equal to any values just yet so I'm going to make an array called Bucky and Bucky can hold nine integers so in this line of code we're pretty much telling our compiler and compiler whenever you run this program you better set aside some space in our memory enough space to hold a nine integers so our compiler says yes sir now what we need to do is well let me just go ahead and whenever I'm done with this tutorial I'm going to print out the elements on one side and the value so I might as well give it a nice little prompt now element and value so what we're going to be doing is we're just going to print out the element on one side and the value on the other side so let's go ahead and take a look at this right now one space for elements and I'm going to list those on this side and right across from it I'm going to list their values right here so we're saying all right you talk to talk now time to walk to walk one way to create an array like I said before is the use of loops and in this tutorial I'm going to be using the for loop so let's go ahead and see what parameters we add for this so we already know that whenever we create an array that holds the nine elements every array starts at zero so I think whenever we created this int X zero would be a good place to start and we also know that if we created an array that can hold nine integers the last index in that an array excuse me the less index in that array is going to be 8 because count with me get your fingers out 0 1 2 3 4 5 6 7 8 I only counted to 8 but since we had 0 in there that takes care of our 9 elements pretty cool huh so we only want to loop from 0 to 8 so that's why you're right X is less than 9 we can make it easier X is less than or equal to 8 oops not X comment less than or equal to 8 either way it works fine X is less than 9 is a little bit quicker but you know what's one extra character so now of course we're going to use X plus plus the increment X by one each time so now whenever we see out X and line let's go just go ahead and run this real quick so I can show you guys we get that 0 through 8 and you're saying that's pretty cool so now we have the numbers 0 through 8 and those just happen to be the exact numbers that we need in our array so now what we can do is something like this Bucky X equals 99 or something stupid so what this is going to do is it's going to go through your array each element one by one and assign the value 99 so the first time it loops it's going to set the Bucky zero element to 99 the next time the Bucky one element to 99 so it's basically going to set every element in your array to 99 until it gets to eight and then it's going to do it one more time and stop at 9 so pretty cool huh so let's go ahead and print this out and see exactly what I did so see out first we'll go ahead and print out X which is the element number same as this so this is going to be 0 through 8 on the left-hand side and now just go ahead and give us some space to work with and after this just go ahead and write the value of whatever element is stored in there so this is going to be 99 if we coded it correctly so let me go ahead and end this line and whenever I run this you guys will clearly see what's going on so what we did is we loop through each array element one at a time first Bucky 0 then Bucky 1 the monkey 2 3 4 all the way to 8 in each time we loop through it we set that element equal to 99 so now we have an array called Bucky that has nine elements 1 2 3 4 5 6 7 8 9 and each of those elements is equal to the value of 99 there are actually a lot of nines in this soil but you know it's good number so you know it feels appropriate so let me talk you guys through this one more time in the code in this line of code we're basically declaring a 9 element Bucky array we're telling our computer make sure you set set aside enough space to hold 9 integers in the array Bucky so it that's what it did in this line and this line all we did was print out a title basically and in our loop we knew that since we're creating Bucky 9 array that the indexes that it need was 0 through 8 so we made a simple loop that basically loop through the numbers 0 through 8 in with those numbers we could reference the Bucky element and assign it equal to the value of 99 for each one and then of course we just printed out the index which was 0 through 8 and then the value which was 99 each time so simple enough so that is basically two different ways to create an array um again whenever you're working with a really big arrays in I don't know it's just a lot easier than using an initializer list because if you created an initializer list with like a hundred values then you would go ahead and have to type a hundred values in here and it will just get messy really quick so this is a faster way um it takes a little more thinking but it's definitely worth it so for now that's all I have for you guys thank you thanks for watching don't forget subscribe and I will see you next door Oh welcome back eyes through 34th C++ tutorial and in this lesson I'm going to teach you guys how to use an array in calculations and it's actually a pretty simple program definitely useful definitely something you want to stay tuned for so let's go ahead and make an array right now let's call it tuna I'm getting tired of using Bucky every time and let's set the tuna array big enough to hold five integer values looks good enough and now let's go ahead and use an array initializer list um let's go ahead and throw in 2050 476 832 and whatever this number is right there so now we created an array called tuna and it has five different elements or five different values in it so now what we want to do is say our boss came to us are a teacher and he's like build a program that calculates the sum of all of these elements so we're saying all right the first thing we need is a variable to hold that sum and by default since it doesn't have any elements at first we're going to set it equal to zero so what we could do is this sum equals looks I try to type Bucky again tuna zero plus tuna oh you know what I'm getting a bunch of typos and this is just taken too long not very efficient way of doing it although it would work so let me go ahead and show you guys a much easier way to use an array in calculation so instead of all that typing let's go ahead and make a for loop instead so now what we need to do is just like before find out which array index is our array is going to need and just use our for loop to loop through those array indexes so of course as always we need to start at zero because the first index in every array is zero alright now let's do a little bit of thinking but not too much tuna holds five values so that means the last index in that array is four so if you're right X is less than 5 what it's going to do is going to go from zero to four it's not going to do five because five is not less than five so now when you press X plus plus we now have a four loop that loops from zero to four so it's going to go zero one two three four those are going to be your X values so what we can do now is just use some plus equals tuna X now what this is going to do is this the first thing it's going to do the very first time it runs the loop is going to say this all right X is equal to zero so add tuna zero which is 22 the sum now the sum is going to be equal to 20 the next time it's going to be one so add tuna one which is 50 for equal to the sum which is 20 so now it's going to be 74 so it's going to go through each of these elements one by one and add each value to the value of sum so let's go ahead and just print out this on the screen um see out some end line and now you can see a better idea of what's going on so like I said one by one the very first time it runs it's going to add tuna zero equal to sum the next time tuna one equal to some tuna - two - three - four so if you add up all these values right here you get the value of 1528 so one last time what we did is this we created an array called tuna using an array initializer list that holds five integers 1 2 3 4 5 now what we wanted to do is we wanted to calculate the sum so we made a variable called sum and of course by default since it didn't have any value we set equal to 0 then we made a for loop using the value in here excuse me the variable to loop through each index of our array so it started at 0 and since we know this one was two and a four that's what we put for here X is less than five and of course we want to go one at a time we don't want to skip you know this one in this one or anything so then what we did is we loop through each value and added it to the variable sum and then we just printed out some on the screen and that's what we got 20 74 115 9 82 15 28 so that's a real simple program in order to use arrays and the array indexes and elements and values and calculations yadda yadda yadda all that fun stuff so now you guys know how to use arrays in calculations you're ready to move on to my next tutorial we're going to be talking I'm going to teach you guys something else about an array that's actually pretty cool so don't forget to watch that tutorial thank you guys for watching and don't forget to subscribe what's going on guys welcome to your 35th C++ tutorial and in this tutorial definitely don't want to miss this one because I'm going to teach you guys how to pass arrays into functions and there are a lot of weird tricks that you need to watch out for so make sure that you pay attention to every single detail so let's go ahead and make a really simple function I'm going to make it really easy the only thing it's going to do is print out an array you know one by one so far array was like 4321 eight it will print out 4321 eight really simple but you know it's a nice clear example so let's go ahead and make sure you're working outside your main function right here and call it anything you want I'm just call mine print array and it's going to take some parameters the first parameter that's going to take is the array itself that we're going to pass it in so let's go ahead and say we're passing it in an integer array go ahead and write int and then give your rate a name the array and whenever you pass an array into a function you need to write those square brackets right after it if you don't write those square brackets it's going to think that you're going to try pass in a variable and we want to tell our compiler no our first parameter whenever we use this function is going to be an array hence the square brackets so what people typically do whenever they pass an array into a function they usually want to pass in the size of the array too because you know that's information that you definitely need to know later on so just go ahead and name the size of array and this is of course going to be how many elements are in the array so now like I said this is the easy part let's just go ahead and build a function that prints out on you know each element in the array so for int x equals zero because remember we always want to start at a zero so that's never going to change the only thing that's going to change is this second thing we need to pass in X is less than size of array so check it out we can go ahead and write you know later on when we create our array instead of using size of array x is less than 10 or X is less than 20 but now whenever we use this function we can pass in any array and any size we want and it's going to work perfectly so instead of setting this equal to a number like 10 15 5 I like to set equal to a variable because then it's a lot easier later on and of course X plus plus incremented by 1 so now whenever we pass in an array it's going to loop through each of its elements 0 to the last element so now let's just go ahead and print out on the screen the array and of course for here we plug in X and endline so now once I fix this right here what we built is a function that bit basically takes two parameters an array and the size of the array we needed this information because whenever we created our loop we needed to know how long to make that loop last and of course for each line all we did is we print out whatever element whatever value that element is equal to so now let's go ahead and prototype this function right now because remember we're going to be using the function right here in the main but whenever it tries to use this function it's not going to know that it's a function that we built in less we prototype it so let's go ahead and copy this and if you remember from like I don't know the 10th tutorial something around then if we prototype it now we don't get an error message whenever we try to use this function because it knows that it's a function that we created so let's just go ahead and make two arrays to work with int Bucky and we'll set this equal to a 3 injury and go ahead and add any three integers you want um 20:54 and 675 sounds good to me and actually let's go ahead and make another array just to make sure our program is working fine I like to name my arrays names and I'm going to name this one Jessica and she's going to hold 6 integers so set this equal to get that elbow way and 54 on why do I use 54 L time 24 7 8 & 9 and how many is that 5 and another 199 good go so now we have 2 arrays Bucky which has 3 integers and Jessica which has 6 integers so whenever we want to use this function that we just created just go ahead and type the name of your function print array and give it the two pieces of information needs but you know I have to begin this story I said that there are a couple of tricky things that you guys need to watch out for this is one of them you might think in the first parameter you might type Bucky or Bucky square brackets or Bucky square brackets 3 but actually the only thing you type is the name of that array so of course you well how can I explain this you already created an array called Bucky so now whenever you pass it in it knows it's on the right you don't have to tell it that you're passing in an array because obviously if it created it already it's going to know so that's why whenever you pass it into a function you don't use those square brackets at all and of course the second piece of information it needs is how big is this array so let's go ahead and make sure 3 and passing 3 4 here so now let's go ahead and build and run this program and check it out 20 20 54 54 675 675 and now let's go ahead and use this for Jessica just cut array again with no square brackets and six so let's go ahead and build and run this and it looks good to go 54 24 seven eight nine ninety nine pretty good so one last time here's what we did in the very first line of code we built the function prototype because if we didn't have that prototype let me just go ahead and comment this out and we try to run it we're going to get an error message so this error message pretty much means this our writes I did this I did this and now you want me to do this what the heck is print array so when we do include that prototype and try to run it it knows that Oh print array is actually a function that you guys built alright so now I'm going to run this and I know to look for a function so anyways that's what prototyping did in the main we just made two arrays and in this line we just called that function and passed in the array name and the size of the array so then whenever we called Jessica six it went down here to print array for this parameter it was Jessica and for this parameter it was six and then it looped through it pretty much looped through a loop six times and said all right for the array which was Jessica print out each index of that array zero to five and that would give you your six elements so this is basically how you use an array in a function and the only couple things you need to watch out for is this don't forget to prototype your functions don't forget whenever you are making your function itself to include the square brackets but whenever you use the function in your main program do not include the square brackets because your compiler is smart enough to realize that whenever you use Jessica it obviously is an array because you told it right above it so as long as you remember those simple things you will be good to go and that is how you use an array side of function so it's kind of complicated at first but if you just do it like two times you'll be a pro at it so that's all I have for you guys for this story thank you guys for watching and don't know when we talk them out in the next tutorial but it's going to be cool so I'll see you then what's going on guys welcome to your 36th C++ tutorial and in this story I'm going to talk to you guys about something called a multi-dimensional array now a multi-dimensional array is basically an array inside another array so yeah I think about that for a little bit and get freaked out you might be thinking whoa this reminds me of Inception a dream within a dream what's going on and you guys are thinking oh man this tutorial is going to be super confusing I barely even understand arrays and now you're going to say an array inside an array all right well here is an easier way to think about it if you ever you know use Microsoft Excel or maybe use MySQL think of it as a database or a table a multi-dimensional array is basically made up of rows and columns so this is the easiest way where you can think of it in its basically whenever someone has information and they want to organize it in rows and columns they use a multi-dimensional array so let's go ahead and create one right now and I'll show you guys the syntax for it go ahead and pretend you're creating a basic array I'm going to name mine Sally and instead of a 1 square bracket actually takes two square brackets in the first square bracket you write how many rows do you want to have in your array let's let's keep it simple and say we want to have an array with two rows and for the second one it's basically columns how many columns do you want to have in your a so let's go ahead and add 3 columns so now we have a row excuse me now we have basically a table that's two rows by three columns aka there are six elements in this array so in order to create um an array inside an array it's basically exactly like you would think go ahead and make your array and just to tell you guys this code blocks gets freaked out whenever you try to put square brackets inside other squirly brackets so that's why it might be messing up when you try typing it but anyways go ahead and as the first element in your array you actually add an array so let's go ahead and add two-three-four so check it out we have an array two three four inside another array and this smaller array is the first row so now let's go ahead and make our second row or second array add a comma and like I said codeblocks gets freaked out whenever you try to do it so it might be weird but let's go ahead and in this array put eight nine and ten so we basically made it two different arrays one array is two three four and the other array is eight nine ten so we said our a we're creating a multi-dimensional array consisting of two different arrays each array is a row in each value is going to be a column and remember to separate your arrays with a comma so basically this is an array made up of two smaller arrays so let me go ahead and draw this for you guys visually like I said there are two different rows one is two three and four and the other one is eight nine and ten so visually this is what our array looks like this is all one array that's basically made up of this array 2 3 & 4 and this array 8 9 & 10 2 3 & 4 is on top 8 9 10 is on bottom two rows three columns pretty simple huh so anyways the basics of this is anytime you want to create a multi-dimensional array go ahead and list number of rows number of columns and for the number of rows that's how many arrays you create and for the number of columns that's how many values you add to each array and then you end up with something like this so if you're saying alright now how do I reference you know how do I get to each element in that array well let's go ahead and just print it out on the screen um of course print out Sally and whenever you reference it it just takes the two brackets the first index you need is what row is it in and remember the first row starts with 0 so anytime we want to access element in this first row we need to go ahead and put 0 now remember 2 is going to be 0 oh three is going to be one and four is going to be two so if you're right zero two it's going to look at the zero with Rho which is the first run and the second element which is actually zero one two so it's going to go zero two and that's going to give us our four it's basically just like coordinates I don't know why I didn't say that before I didn't cross my mind but basically multi-dimensional arrays are exactly like coordinates you're asked the coordinate here start with zero in the coordinate here so if you want to reference nine that would be zero one so go ahead and type one for that and zero one right there so that let's go ahead and print that out and I got my nine so basically a multi-dimensional array just like Inception is an array or more than one array inside a bigger array it's pretty much an array made up of arrays instead of values and what it does is it gives you the idea that you can create a table basically made up of rows and columns and anytime you want to access one of the elements you just go ahead and type in the coordinates which would be the row number and then the column number and you print it out and there you go so if you guys understand this then you're ready to move on to my next topic in next tutorial I'm going to teach you guys a really simple way to print out a multi-dimensional array so instead of you know just having to comment this right here you have a nice visual of what it looks like so if you guys don't understand it then go ahead and just go to my forum and ask me a question and I'll explain it better there but if you do or you know maybe if you've got any good inception jokes then leave them in the comments below but for now thank you guys for watching don't forget to subscribe and I will see you in the next tutorial alright guys welcome back to your 37 C++ tutorial and in this is tutorial I'm going to show you guys a really easy way to print out multi-dimensional arrays so let's go ahead and first thing we need to do is create a multi-dimensional array go ahead and name it Bertha and Bertha can be two rows by three columns same as before so now what we need to do is go ahead and make an array of arrays so the first thing I do is put my two arrays in there separated with the comma so now we have two arrays which would be two rows and now put three values in each like um we'll just put one two and three in the first one and seven eight and nine in the second one so now we have an array called Bertha that has two rows and three values in each row so it's basically a table that's two by three so in order to print this out what we need to do first is we need to loop through each row one by one we're going to loop through the first row and then we're going to loop through the second row so let's go ahead and make a for loop and int well we might as well name this row and of course it always starts is zero because the zero if index is the first element in your array so row zero and the second one is Row is less than two so what this is going to do when we put row plus plus is it's going to go from zero to one so row zero then Row one it's not going to go row two because of course two is not less than two so now we're looping through each row one at a time and now of course you guys can probably guess what I'm going to new next we need to loop through each column or each element in the row so now in order to do that go ahead and make another for loop and this is going to look really familiar familiar there we go int column make sure I spelled it right this one starts at zero as well again all array start at zero even there even if they're inside another array column is less than three because that's how many columns you have you basically write the maximum the number of rows in the number of columns right there simple enough you know what that kind of looks like a heart hmm that's kind of cute anyways moving on column plus plus so now what we're doing is this we're looping through each row one by one the first time it loops through Row one it's going to loop through each of those elements 1 2 & 3 and then it's going to loop through Row 2 and then it's going to loop through each of those elements 7 8 & 9 so after we get through looping through each column we want to move to the next line see out and line because again each row is on a different line so that's why when we're done looping through the last element in the row we want to move to the next line so now we can just go ahead and print it out on the screen like see out a Bertha was your name and you put the row number which would be this 0 or 1 and then you put the column number which is going to be some value 0 to 2 and that would be these values right here so let's go ahead and make sure you don't write end line on actually what we do need to do though is add a space there but make sure you don't write end a line on this line right here because these are your column values you don't want every single one of these numbers to go on new line you only want it to go to a new line after you're done looping through the last element in that column so let's go ahead and print it make sure I didn't forget any semicolons which I did somewhere and let me see what's wrong are oh I see what I did here is I put a call come on eyelet put a comma instead of a semicolon so now let me check make sure to run it again and there we go in our first row it printed out one two three and in our second row it printed out seven eight nine so this is a perfect way to visually see multi-dimensional arrays so pretty cool huh so again one last time here's what we did I'll just leave this down here we made an array that was two by three and what that means is it was an array consisting of two different arrays with three values each and what that means is basically made a table that was two rows by three columns as we can see right here the first thing we needed to do is loop through each row loop through this row the first one and then loop through the second one and we did that by writing row 0 rows listen to yahya data all that fun stuff you basically the only thing you need to worry about is make sure this value right here is the same as this value right here so we said all right for each row we loop through we wanted to loop through each one of the elements one at a time so that's why I wrote start with zero one two one at a time and why we had this little spacer right here is because if we didn't have that it would put one two three real close together so what it did is it basically printed out a row one element at a time and then when it was done it said see out end line and that's why it jumped to this next line and printed out seven eight nine and it did that until it was done printing out all the rows and then it just ended so that is how you print out a basic multi-dimensional array again of course this is a whole lot to see visually it's a whole lot better looking at than this right here so that is why you actually use this quite a bit whenever you're programming so that's all I have for you guys for this tutorial thank you guys for watching hopefully you understand how to print out a multi-dimensional array now because we're going to be done talking about arrays for now in the next tutorial I think I'm going to be covering something called vectors which is kind of like an array but it's a little bit different so thank you guys for watching don't forget to subscribe if you have any questions check out my website and I'll see in the next video alright guys welcome back to your 38th C++ tutorial and in this tutorial I'm going to be beginning to talk about something called pointers now pointers is something that confuses a lot of people so I'm going to try to explain it really simple for you guys now you remember how we made some variables that contain strings of text and we made some variables that contain integers and we made some variables that contain floats well a pointer is a special type of variable that contains a memory address as their value pretty weird huh so let's go ahead and the first thing we need is a plain old integer variable so let's go ahead and make a variable called fish and set it equal to the value of 5 it doesn't really matter what the value is to be honest so anyways we have a plain old variable named fish now let me go ahead and show you guys how to retrieve the memory address of this variable so as you probably already know this variable called fish is stored somewhere on a computer somewhere in the memory you know who knows where so sometimes we need to be able to access where indeed that memory is so in order to do that you go ahead and you write that and sign and the and sign is called the address operator and now whatever variable you type after it this means the address in your memory of fish so if we go ahead and print this out on the screen using C out and might as well end that line hello can't type in line today and L there we go I'm going to go ahead and build and run this we see that we get this weird hexadecimal who knows what this is this is actually the memory address of where the variable fish is so again like I said the first thing we need to find the address of something is of course a variable because we need to find the address of something and in order to find the memory address of the variable you go ahead and you write the and sign right before the variable and then those two combined pretty much tell your C++ compiler all right I want to print out the memory address of fish not the variable fish itself so this is of course the address of where your variable fish lips now you're saying all right well you just want over address operators I thought you were going to go over something called pointers well let's get into that right now a pointer like I said is a special type of variable that points to a memory address in other words um a pointer is a variable that contains memory addresses a value so let's go ahead and I'll show you guys how to make a pointer in order to make a pointer go ahead and write the type of data you're going to be pointing to so we're going to make a pointer that points to an int value or in other words an int variable so this is going to be an int pointer simple enough now in order to tell C++ we're making a pointer instead of just another variable we need to add an asterisks that little star above the eight on your keyboard and now we can go ahead and name a variable like fish pointer and this tells our compiler that we're going to be making a pointer instead of a regular variable again if we just had it like that our compiler would think that we're just making a regular variable but we're not we're making a pointer so that's why we needed that little asterisk before fish pointer so we went ahead and we declared a fish pointer right here pretty much telling our program we're going to be making a pointer called fish pointer and what this fish pointer is going to do is it's going to point to a memory address so now we have to of course assign a memory address so let's go ahead and whenever you assign a memory address to a pointer you don't need to include the star again because you only do that whenever you're first creating the variable from now on whenever you use the variable fish pointer C++ already knows that it's pointer because you told it whenever you created the variable so make sure you don't put star fish pointer twice only one time C++ is smart enough to recognize this now go ahead and set it equal to the memory address of variable and we only got one variable fish so now fish pointer is equal to the memory address of fish it isn't equal to five it is an equal to the word fish fish pointer is equal to the memory address of where the variable fish lives that long hexadecimal thing so now when we go ahead and see out print fish pointer and go ahead and then that line now these two lines should be identical because first we're printing out the memory address of fish and next we just are basically printing out the memory address of fish so let's go ahead and make sure these lines are the same so I don't look like a fool and see there we go so basically we know how to print out the memory address of a variable using the memory address operator that's a pretty nice name for it so then I taught you guys how to create a pointer and all a pointer was a special type of variable that had a memory address as its value so again whenever we ran this we can't assign this to an INT because it's not an integer we can't assign it to a float because it's obviously not a float so we have to assign it to a special type of variable called a pointer so that's why you need to be able to use pointers and of course when we just printed it out it printed it out the memory address pretty cool huh so that is your basics of what a pointer is how they're created and how you obtain the memory address of a variable so now with all that knowledge we can begin programming and we're actually you're going to use these pointers and programs and they're actually useful for something believe it or believe it or not so thank you guys for watching and hopefully you understand everything in this story if you have any questions don't forget to check out my website the new Boston.com and I'll see you guys in the next tutorial what's going on guys welcome back to your 39 C++ tutorial and in this story we're going to be covering pass by reference with pointers and we actually have a ton of stuff to cover so I don't even know if I'm gonna have enough time in this one store oh I might have to break it up into two different tutorials but let's go ahead and get started anyways so we already know from our last tutorials that whenever we pass an argument into a function passing argument into a function basically means giving our function any additional information that it needs like in order to calculate the square root of a number you actually need a number so you have to pass a value into that function but believe it or not it isn't quite that simple there are two different ways that I'm going to be teaching you right now they're actually more than that but for now I'm going to be teaching you two different ways to pass arguments into functions one of them is passed by value and one of them is passed by reference now what do I mean when I say that what we've been doing is basically passing by value and whenever we create a function and we pass it by value we pass a copy of that variable into the function so the original variable itself cannot be changed until we set it equal to another value so that way the function only has access to the copy of that variable not the original variable itself simple enough values pretty much mean passing in the copy okay now pass by reference means this whenever you pass in a variable by reference you pass in the variables address and whenever you do that you basically give the function direct access to that variable so in that sense the original variable can indeed be modified inside your function so why would you ever want to do that it seems kind of dangerous well the one benefit is it's basically less stress on your computer instead of passing by value where every time you call that function it has to make a copy of the variable suppose you had 100 variables that would be pretty stressful on your computer if you pass by reference and you pass in the value itself it doesn't have to make copies of every variable so let's go ahead and let me start off by making two variables int Betty and I'll set this equal to 13 and let's make another person int sandy and set this equal to 13 to now what we're going to be doing is passing this one in by value and passing this one in by reference and see how they turn out so we're going to be needing to create two different functions first let's go ahead and create a function that we're familiar with pass by value so void pass by value and let's just go ahead and create a basic function it will take a parameter of one integer and what we're going to do is take this integer and set it equal to 99 so basically we're going to be doing is Betty pretty much X is a copy of the variable Betty so then whenever we set X equal to 99 it doesn't set Betty equal to 99 it just sets this copy equal to 99 so that's what's going to happen now let's go ahead and make a function pass by reference so void pass by reference hopefully I spell that right there are way too many E's and efference reference for YZ I mean come on guys enough of these so functions that receive a memory address they need to have a pointer argument because they need to have a pointer because a pointer is the thing that receives the memory address so now instead of in X you need to type int pointer X because the pointer X is now going to be able to hold that memory address so now when I whoa one little extra thing there so now what we can do is something like this points or X is equal to 66 or something like that so now instead of the copy of X being to 99 and now the variable itself sandy X is the address of Sandy so sandy is going to be changed at 66 so whenever we pass Betty in this one her values not going to be changed whenever we pass sandy into this we're basically passing in sandy directly into this value into this function her address and everything so now this is a direct access to the variable sandy so let me go ahead and first of all we need to prototype these functions so copy this and paste got a copy it or did I just do something weird I might've had a extra character somewhere better not get error out so I'm going to be ticked off so copy that and then copy this reference and pass paste this in and now check it out before we go ahead and well let's go ahead and just use these right now and then I'll talk to you guys about the thing I was going to so let's go ahead and pass by value and we will pass Betty into this one so we're going to pass 13 in that but her value isn't going to be changed now let's go ahead and pass by reference sandy and we're pretty much given this function direct access to sandy so that value is going to be changed so now what we need to do is here's what I'm going to talk to you guys about since we're passing in the memory address of course you remember from the last tutorial we need the ampersand because sandy is the variable and this function takes a memory address so the symbol for the memory address of the variable is ampersand sandy this is basically equal to some long hexadecimal address of where that variable is located on your computer so now let's just go ahead and print out the values and see what we get see out arm Betty is now and then just go ahead and print Betty and end the line and now do the same thing for Sandy is now sandy and lime so let's go ahead and run this in I guess I can see if I messed it up anywhere nope looks good so as you can see we basically built identical functions however when we passed in Betty it stayed 13 and when we pass it in sandy even though it was 13 it changed it to 66 so now you can see whenever we pass let me move this down right here whenever we pass a variable into a function we can do it in one of two different ways we can pass a copy of it like we did in the Betty case pass by value and what this does is it basically makes basically X is a copy of Betty it doesn't have any access to Betty itself it's just a variable with the same value so then we set X equal to 99 it's just setting 99 equal to that copy not Betty itself so if we pass by reference what we do is we take the memory address of that variable and remember your memory address is some part on your computer it doesn't make a copy of it it passes in that memory address itself that memory address has the value of 13 and we're saying alright now take that memory address and set it equal to 66 so no copies involved here it's taking that same address the entire time and changing the value of it so now you can see the difference of whenever we use a function like this it makes a copy and we get whenever we use a function like this it works with the direct variable itself so that way whenever we ran the two functions right here and printing it out on the screen that's why Betty stay the same because that copy had no effect on the original and sandy changed because it did indeed change the value of that one address that variable was only a one address and we passed it in so it had direct access to it so I am out of breath and hopefully you guys understand at least the concept of pass by value and pass by reference just remember when passing by value you're passing in the copy when passing in reference you're passing in the variables address if you understand that you're good to go at least for now so in the next tutorial I'm afraid we're not done well I got like Fleming my throat I can't talk I just had a milkshake for McDonald's and anyways moving on so in the next tutorial unfortunately we're not done covering pointers yet so yep more about pointers I'm sorry so thank you guys for watching don't forget subscribe and I'll see you guys in the next video alright guys welcome to your 40th C++ tutorial and in this tutorial we're going to be taking a quick break from pointers and we're going to be covering something on the size of function now the sizeof function is actually a function that you use a lot when working with pointers but for this demonstration just to give you guys an idea of what the sizeof function does I don't want to include pointers because that's too much information for one tutorial so we're just going to be seeing a simple demonstration of the sizeof function and then later on we can apply it to pointers but for now let's go ahead and check it out so what the size of function does is it basically determines the size of either array or maybe a variable or a constant it pretty much determines the size of something in bytes and remember bytes is just the size of memory like 4 bytes 1 byte yada yada yada so let's go ahead and make a basic variable um I don't know if I tell you guys the chart yet but char just is a variable of character type it basically sword's a character so let's go ahead make a variable char and we'll call the variable C let's go ahead and see how the sizeof function works so you go ahead and type size of and then in the parameter you type what do you want to get the size of well let's just go ahead and get the size of this variable right here and then we'll just end that line and that's it you go ahead and run it and outputs the size of character which is one byte so any character we store in our computer it takes one byte of memory all right simple enough so let's go ahead and make another type of variable like um an integer variable so how many bytes do integers take up on our computer well if you don't get the same number as me don't worry but because every computer is a little bit different on my computer an integer takes up four bytes of memory so again if you have like a 2 or a or maybe you have 4 same as me I you know don't think you're running the program wrong every computer stores memory differently mine says 4 so anyways we know that a char takes one bite an integer takes 4 bytes and now let's go ahead and see double well we already know an integer can store numbers without a decimal point and those take up four bytes a double is pretty much a more precise integer so that's why whenever we run this we're expecting to see 8 bytes or something higher than 4 and the reason that doubles take up more memory than integers is because they're more precise so anyways what I want to stress is the more precise a value is the more memory it needs to take up so that's all I wanted to stress in now let's jump into something else instead of gee these basic datatypes let's say we had something like an array now you know an array is basically like 10 integers strung together or you know maybe 15 double strung together so let's go ahead and make a double array and we'll call it Bucky and it can store 10 doubles now remember a double took up 8 bytes on my computer so we have an array of Bucky and it has 10 doubles we're expecting to see 10 times 8 bytes so this entire array should take up 80 bytes of memory so let's go ahead and see if our prediction is right size of Bucky you go ahead and just write the name of the array in there and then go ahead and inline not Ned line and line there we go so now whenever we run it check it out 80 bytes right there and that is because each double is eight bytes and we're going to store ten of them so that's why this entire array took up 80 bytes of memory simple enough but you're saying all right so I know what the sizeof function does but why would I ever need to know you know the size of bytes I mean that's the computer's operating systems from I really I'm just the programmer I don't have to worry about memory that much well one useful way you can use this function right now before I you know jump into pointers and all that stuff is maybe you want to find out how many elements are in our array so you know maybe you had the user make an array or something and you know how many elements ahead and you need to know how many elements this array had in order to make a calculation well of course we know that this array has ten elements but say we were trying to figure it out it anyways something you can do is this see out what you can do is get the size of Bucky remember this would give you the 80 bytes this is the entire size of your array 80 bytes and what you do is divide it by the size of one element and do that just go ahead and write size of Bucky zero which is the first element and then whenever you printed it out in line you should get ten so let's go ahead here's the 80 before and now we get 10 which means ten elements in our array and again why did this happen what we did is we took the entire size of our array Bucky which was 80 bytes and we divided it by one element size which was eight so 80 bytes divided by eight bytes gives us ten elements so again any time you want to get the number of elements in your array say you know couldn't see that line for some reason take the entire size of your array and divide it by the size of one element and your answer is how many elements you get in your right so again here is a basic example of the size of again all we did is find the size of different you know data types arrays variables yadda yadda but later on we're going to be using this to work with pointers and it's actually a lot more useful than just finding how many elements are in your array so you know now you guys know the size of now whenever I teach you later on you won't get confused so for now thank you guys for watching don't forget to subscribe and I will see you in the next video alright guys it's time to jump back into pointers and specifically in this tutorial I'm going to be covering pointers and how we can use math with pointers and even more specifically I'm going to show you guys you know how to add integers to pointers and why the result isn't exactly what you might expect so let's go ahead and start off by building a basic integer array I'll call my Bucky and it can hold five integers now we already know that each integer on my computer takes four bytes of memory on the older computers they usually either take up two bytes or four bytes on some of the newer computers they might take up eight bytes so you know if you're running this tutorial with me and it's not the exact same results don't freak out it's just how your computer stores integers so let's go ahead and make a couple pointers I'm going to make a pointer named BP BP 0 and this is going to be equal to the address of Bucky zero in other words it's going to be equal to the address of the first element so let's go ahead and print this out right now and see what the address is so on just give a nice little prompt like BP zero is at memory address and let's print out BP zero that will print out the memory address and of course that's in that line so now let's go ahead and build and run this and we see that BP zero is at the memory address ff0 eight okay simple enough so since we built an array and since we know that each integer takes up four bytes we're expecting the next pointer well let's go ahead and build a couple more pointers first and we're expecting the next pointer to be a memory dress for away from that so if that one was eight the next one will be at twelve and the next one will be at sixteen so let's go ahead and one this will point to the second element and this will point to the third element so now let's go ahead and print all these out on the screen and when I do we can clearly see what's going on 1 & 2 & 2 so basically we're bringing out the memory address of this and then the memory address of this and then the memory address of this so let's go ahead and print this out and check it out bp0 is it location FF 0 0 and since we're storing integers and they take up 4 bytes the next one is 4 bytes away FF 0 4 the next one is 4 bytes away FF 0 8 and if we were to go on I'm not going to but we can clearly see that each integer takes up 4 bytes of memory on our computer and since we're building an array all these integers are stored one right after each other so that's why each element in our array is stored 4 bytes after the next one basically whenever you make a ninja on computer it reserves 4 bytes of memory for it and you know nothing else can go inside that memory except that integer so let's go ahead and say we're playing around and we decided to do something stupid like be p0 and we set it to add to 2 you know this memory address so let's go ahead and put plus equals 2 well now let's go ahead and print out the address of b p0 again and see what happens remember before it was stored at arm the address FF 0 0 so now when we add it to to it we should probably be expecting this to be a FF 0 2 but let's go ahead and run this to see what happens okay like before the first element will store to FF 0 0 then F F 0 4 for the next one then FF 0 8 for the next one but what we did is we took this first one FF 0 0 and we added 2 to it so we should be expecting an FF 0 2 right makes sense that's how it works in our brain but our computer said b p0 is now it ff0 eight well that was the address of this one right here so what is going on what happens is because pointers don't work like math works in our head whenever you add integers third pointer it doesn't change the memory address of that pointer it only changes what element it's pointing to so for example whenever you run this and we try to add two to this pointer right here it didn't change the memory address right here what it did is said all right I'm going to take your pointer and add two to it and basically I'm going to point to whatever is two elements away so again what I want to stress is whenever you're working with math and pointers you're not changing the memory address you're only changing the element that appoints do so again you're not changing this piece of memory right here you're changing what element it's pointing to simple enough like I have a really hard time explaining that but you guys can see what's going on so for example if I put be p0 plus plus it wouldn't change it to FF 0 1 it would change it to FF 0 4 because let me go ahead and prove it to you guys first so we added 1 to this it didn't change the memory to 0 1 it changed it to 0 4 because 0 1 it would overlap this one which would overlap this one and cause a whole bunch of problems so what it does is and change it instead of changing the memory address it just says alright if you're adding 1 to this pointer then you probably want to just point to this pointer right now so that is basically how pointer of Arithmetic works basically instead of changing the memory address it just changes where it points again you guys can clearly see in this example what's going on so you know just look at it and you guys can probably understand that a whole lot easier than me trying to explain it so there you have it that's how pointers work with math and why you might be getting a different result than you might expect so thank you guys for watching don't forget subscribe in the next tutorial no idea what I'm going to be covering but I'm probably going McDonald so you guys chill out wait a couple seconds and I guess I'll see you guys in the next door alright guys in this video I'm going to be showing you guys what the arrow member selection operator does and when you should use it but I was thinking and I was like you know what we haven't created a new class in a while and it actually would be kind of useful in this tutorial so let's go ahead and start working with the new class so just a refresher from I don't know I probably did this like 20 tutorials ago in order to create a new class press file new class and then you go ahead and name request anything you want I'm going to name mine Sally and I don't think we covered destructors yet so let's go ahead and uncheck those and make sure we're working in the same directory as our main.cpp so everything looks good go ahead and click create and of course it's going to give you these two confirmation yeah of course I wanted to do both of those and now we got two new files a Sally header file and a Sally CPP file and remember the Sally header file is basically where we're going to be making all our prototypes and the Sally CPP is we're going to be doing the actual coding so in our main CPP we need to do a couple housekeeping things first go ahead and copy these and of course it's your iostream and name space and go ahead and copy it right in here and of course we need the Sally header I forgot I always try to right-click and select copy but there is no copy so anyways go ahead and get our Sally header and paste it in our main dot CPP so basically the beginning of main.cpp and Sally CPP should look pretty much the same so now a couple things I like to do actually the only thing I like to do is this go ahead and take out this comment because useless comments annoy me and I guess I might as well go over this one more time in FDF and define and end if all of this means the stuff in green right here they put that there in every class they automatically build for you and it pretty much means don't include a header file if you don't need it this literally means if not to find Sally header file then define it so basically whenever you're running in main.cpp all these classes are going to have it in it's like if you already included Sally header file then don't include it again because you only need to include it once obviously so that's what all that means so now all my explaining we can finally get to the torial so in this tutorial the first thing we need to be able to do is I'm just going to create a random stupid function in the Sally class so in order to do that let's go ahead and it's not going to return anything so I'll just put void and then write your class name Sally and then we need that double colon operator and then print scrap I'd already have my my favorite function stored forming so basically we need this double colon operator again this is a reminder because without it it wouldn't know what function print crap blonk do so we're saying alright this belongs to the Sally class and you know if we didn't have that then we would get a so write your class name double colon and then your function name whenever you're building functions so print crap and all we're going to have this do is see out um very something see like did someone say steak and n line so basically we have the Sally class and we have our constructor function which doesn't do anything and we have this function called print crab that pretty much prints crap out on the screen so now we can go ahead and prototype it and remember whenever you're prototyping in class go ahead and copy that and actually what we need to do is this don't even copy that just under your public right boid print crap and that's all we have to do to prototype it we don't have to copy it because this Sally is basically telling this header file it belongs to the Sally class but whenever we're prototyping the class it already knows that of course we're working with the Sally class so that's why we don't write something like this Sally like that so you know just so a nice little note to keep track of so now that we have basically a class made with one function in it I want to talk to you guys about what I'm going to teach you in this tutorial and that is the arrow member selection operator and that's this little dinging right there saying what the heck is that what's it do what's the point of it well in order to explain you guys what that does let's go ahead and first build Sally objects so Sally make a Sally object called Sally object and we know with our Sally object then we can access the stuff inside the Sally class using Sally object using the dot and then go ahead and you know use what every one use a variable or function or whatever so now when we go ahead and build and run this it says did someone say stake pretty cool huh so we know that these facts are true in order to access stuff from the Sally class we need to use a Sally object and then we can use that by putting the object first using a dot separator and then writing whatever we want to access after it so that is how we access stuff inside the Sally class but now I want to teach you guys that there's a different way to access the stuff inside the Sally class this is by making a pointer to the Sally object so let's go ahead and see what I'm talking about in order to make a pointer you go ahead and write what type of data you're going to hold I'm going to be holding Sally type of data because a class is actually a type of data that you create yourself and now you go ahead and name your pointer using pointer and I'm just going to name mine Sally Poynter and now we set it equal to the memory address of Sally object so basically the Sally pointer is pointing to this object right here simple enough so they're basically the same thing I mean I shouldn't even say that because a lot of people are grammatical pointers and so I'm putting this little drug but you know they're basically the same thing so now what we can do is we can use that pointer to access the stuff in the print crap class I'm going excuse me the Sally class so let's go ahead and put Sally pointer and you might be thinking all right so use the dot separator and then write print crap just like that and I'll try to run this it's going to work fine but why am I getting error message right here and that brings me to the point of this tutorial whenever you using a pointer to access stuff inside a class you need to use something called the arrow member selection operator so again whenever you run this it's going to work fine and dandy so this is accessing it with the object and this is accessing it with a pointer pretty cool huh so it's basically two different ways where you can access things inside a class arm right now I just want to show you guys how to do it and then later on I'm going to show you guys when you would need to do it but not in this tutorial for this tutorial I just want to make sure you guys understand this information you have two different ways of accessing things inside of a class one way is to use an object and then you know the function name and another way is to use a pointer and then the function name or variable name whenever you use an object you use the dot separator whenever you use a pointer you use the arrow and that's actually pretty easy to remember because whenever you're using a pointer it kind of looks like a pointer so I mean it's not can't get easier to remember than that so that's all I want to teach you guys for this tutorial hopefully you understand the concept behind it you probably don't understand why you would use one versus the other but you will later on so for now just understand this and don't forget to make sure that your beginning of all your dot CPP files are basically the same so that's all I have for you guys for this tutorial thank you guys for watching them to subscribe and I guess I'll see you guys in the next video what's going on guys welcome to your 43rd c++ tutorial and in this tutorial I'm finally going to be explaining to you guys those things called deconstructors you know whenever we created class and said automatically create a Deconstructor or whatever and we had it unchecked well I'm going to explain you guys what they are when they're used and then you know when we're creating in class from now on we can understand what they mean so the first thing I want to say is a Deconstructor is basically code that runs automatically upon the destruction of your object and that's the technical term for it but basically at the end of your program one all your memories getting freed up in your programs ending and all your objects are getting destroyed and you want a less a little bit of code to run that's when your D constructor is going to run so you know as soon as you create an object the constructor runs well as soon as it's deleted the Deconstructor runs so that's basically you know when that happens so let's go ahead and first before I even start talking about D constructor let's go ahead and type some code into our constructor like um C out I am the constructor and make sure you spell it wrong and then in that line so now we can see if we go ahead and main dot CPP and create come on keyboard type regular and create a Sally objects so Sally um s o and then after this we really firetruck are you really gonna run right behind me in the middle of this tutorial no that's not annoying well that was kind of annoying but anyways continuing on so we went ahead and we created a sally object now as soon as we create this object our constructor is going to run and all our constructor does is shout out I am the constructor on the screen so now we go ahead and type another line of code like C out armed oMG what DF is this on my shoe or something stupid like that and in that line so let's go ahead and run our program so far so our object was created and it shout it out I am the constructor automatically we didn't have to call a specific function it just did on automatically and then our program ran that said oMG WTF is this on my shoe so now let's go ahead and add a D constructor now to create a Deconstructor it's as simple as this the name of your D constructor is the tilde and that's above the tab on your keyboard but under the escape ill well that's where it is on mine if you look the left of the one umm you see that little squiggly sign it's called the tilde I think at least that's what I call it so go ahead and type that and then type your class name which is Sally so basically your Deconstructor looks the exact same as your constructor except it has that little squiggly tilde above it so now let's go ahead and create the body of it and again it's the exact same as your constructor except it has that little squiggly tilde right before it so another thing I want to point out is this whenever you're creating a destructor it has no parameters no matter what you can never give it parameters also it never has a return value you can't even give it void and aside from that there's no Deconstructor overloading you have one D constructor and that's it you can't have different versions of your D constructor so basically it's a point another fire truck are you serious this is gonna run right past me you guys hear that yeah I'm just continuing on with my story line is and I really don't feel like redoing it so sorry guys so basically whenever your object is first created your constructor is going to run and whenever your object is automatically deleted or you know um destroyed I mean that's the technical term for it your Deconstructor is going to run so let's go ahead and type some code and see out I am the D constructor and make sure you type that very wrong and then go ahead and end that line and let's go ahead and take a look at our main and I'll explain you guys what's going on our first line of code we created a Sally object so right after it right around here our constructor is going to get called in our constructor shouts out I am the constructor so then after this it goes ahead and runs the program OMG WTF is this on my shoe so the next line of code is going to be did is going to be this excuse me now after this line of code is running it's going to see that it got to the end of the program whenever it gets to the end of your program C++ automatically destroys all your objects so by default automatically is going to call your D constructor for this object right here so let's go ahead and build and run this and see what happens I am the constructor OMG WTF is this on my shoe and I am the D constructor so as you can see it automatically called the D constructor and constructor for us so another thing I want to point out is when your program is finished running that's when your D constructor is going to get called so again your constructor in your D constructor you don't have to explicitly column like you would another function inside your class they called automatically and again remember whenever you're creating your constructor it's basically a duplicate the constructor except you need a little tilde right there and unlike a constructor you can't overload it it can't have parameters it can't have a return value and make sure you don't even put void is there a return value it's basically a dumbed-down very simple function so that's the very basics of a constructor and a D constructor and later on I'm going to be showing you guys why D constructor is useful other than just printing out stuff on the screen but for now just understand the concept and I'm going to go ahead and help these firetrucks put out a fire so hopefully in the next tutorial they will stop running past me but for now thank you guys for watching don't forget subscribe and I'll see you guys in the next video what's going on guys welcome back to your 44 C++ tutorial and in this tutorial I'm going to be teaching you guys about a couple things specifically about the keyword Const which stands for a constant now whenever you use the keyword Const it means that whatever you use it on you typically use on variables and stuff it means that that variable remains constant throughout your program aka it can't be changed or modified in any way so let's go ahead and take a quick look at that say you have an integer variable X and you set equal to 3 whenever you first make it and then later on you want to change it to something like 5 while your program is just going to run fine and whenever you try to print out X or use it in any other way it's going to run perfectly fine as expected so what the constant keyword does in that constant keyword Co n St whenever you're creating something you put the constant keyword in there and it's pretty much telling your compiler all right now whenever I create this variable I'm going to set equal to value and I don't want you to change it for the rest of the program so now whenever you change try to change to something else like 5 in try to run this program is going to get error because it's saying hey Bucky you called this variable constant you promised me we're going to change it and now you lied me right there so that's why I'm giving you an error so that's basically what the constant keyword does and make sure that whatever is constant is unable to be modified so that being said later on in your programming you're going to learn that some objects you create you don't want them to be able to be modified some objects are just regular objects and other objects you want constant you don't want them to be able to change so you use this constant keyword whenever you create an object so therefore you have an object that can't be modified and you might be thinking RA so I can just use it with normal functions and not exactly whenever you have a constant object you can't call regular functions with them you can only call functions that they themselves are constant so constant objects need constant functions and of course whenever you create a constant function you need to make sure it's constant both in the prototype in the header file and in the definition aka the C++ source file so let's go ahead and just create a regular function first and then I'm going to be running it aside a constant object I'm going to be doing a couple things so let's go ahead and make um a sally function and we'll just name it like print shiz and this is just a regular function I'm not doing anything weird yet so see out I'm just like I am a regular function and then end that line and then of course since we created a function we need to prototype it so then it is void I think I named it print shiz just like that so now we can see that we can just go ahead into our main program create a Sally object and then we can use that cell object to call our regular functions such as print shows just like that and whenever we run it everything is going to go smoothly it's going to print out I'm a regular function so I did that and we already know that so let's go ahead and jump into constant objects now whenever you create a constant object you do so doing this throw your keyword Co n st before you create your object and everything else is basically exactly the same you type class you want it to be from and also what your name your object like Const object looks like a pretty good name search and IRA all I need to do is Const object and then I can go ahead and call it my other methods like print shiz well whenever we try and do this we get an error message because it's saying alright you created an object that it was constant and you try to use a function that wasn't constant see this function isn't constant is just a regular function so we need to build special constant functions whenever we create a constant object so you're saying alright let's go ahead and do that then so let's go ahead and create another method on a constant excuse me another function talking in Java another computer program language but let's go ahead and create another special constant function so void Sally let's just name this print shiz - and in order to create a constant function you go ahead and you type the keyword constant right after your function definition so Co n s T so now what happens is right after this we build the body for it so this is just going to see out umm I am the constant function just like that and of course we'll end that line right there and now like I said before we need to prototype it is a constant two so we need to basically tell every single file that we're going to be working with constant objects and in order to prototype it here's what we do go ahead and just like before type avoid print chiz yeah that was called printers - and you just write Const right there and now you're telling your compiler alright this is a constant object prototype so a lot of people might think you do this add the Const before make sure you add it after the parameters and you should be good to go so now whenever we try and run this constant function with the constant object remember this is our constant object and this is our constant function print is - now whenever we try and run it it should be good to go I am a regular function I am the constant function pretty simple so so as you can see whenever we build objects if we build a regular object we can use the regular functions with them whenever we build a constant object we're telling our C++ compiler all right this object we don't want anything to be able to modify it or change it so it told us all right I can do that but you need to build me some constant functions if you do that for me I'll run your program just fine so that was our little deal we had with the compiler and that's why this one ran with the right wave function and this constant object ran with the constant functions so now you should understand how to prototype constant functions how to create them and also why constant objects need constant functions and again later on you're going to be seeing why in like bigger programs um you need to be able to create some objects that you want to be able to make constant and why they were useful for your compiler so for now I just want to teach you guys the very basic so in the next story we're probably going to be covering constants a little bit more because there's actually a lot to go over with constants and classes so for now that's all you get thank you guys for watching don't forget subscribe and I'll see you guys in the next video what's going on guys welcome to your 45th C++ tutorial and in this story I'm going to be talking to you guys about member initializers now I don't even know if I told you guys this but a member is pretty much fancy term for anything in your class so when some people talk about variables they call them members it's basically anything in your class is a member of that class so let's go ahead and let me explain this we're going to probably have a bunch of variables in our class some of them are just going to be regular variables and some of them are going to be constant variables so we know constant variables have a couple of weird rules and creating them is one of the weird rules so remember a constant variable is basically a variable that we can't change and we also have to initialize it using a special it's a special syntax it's called member syntax now the cool thing is we can also initialize regular variables this way but you don't have that option of when using constant variables you have the option of initializing regular variables this way or the way we learned before but constant variables definitely need to be initialized using member syntax so let's go ahead and first thing let's go ahead and make two private variables I'm going to make one just regular variable because some be integer variable reg var stands for regular variable and I'm going to make another constant variable so constant just make this one the injur as well and we'll name this one Const var so now we have just a regular doubled variable and a constant variable so now what I want to do is whenever we first create our an object let's go ahead and assign a value to this variable and assign a value to this variable so our constructor is going to take two parameters one value for this one and one value for this one so go ahead and just type in a and enbe and we'll be tossing numbers in there later on but now that we have values assigned to these variables we're going to need a way to print it out on the screen so go ahead and we'll make a function called print simple enough so now we have a constructor that takes two values assigns one to their regular variable one to our constant variable and then we'll print it out on the screen so now we probably need to change our constructor around a bit the first thing we need to make a do is take those two parameters a and int B now you're saying alright I probably go ahead and in the body somewhere in here I'm going to type all that syntax that special syntax you've been talking about but check it out you actually don't write anything in the body yeah think about that for a second it'll freak you out you actually don't write any of your code when initializing variables in the body so you're saying where the heck do you put it and this is the weirdest place you put it in between the parameter list and the beginning of the body so between the parentheses in the curly brace this is where you're going to put it so that's what confuses the most people and that's why they have a hard time understanding because usually nothing goes here but that's where we're going to be putting the syntax why they made it go here I don't know and the syntax for it was this the first thing we need is a colon and the colon tell C++ that we're going to be working with member initializer syntax now it's actually quite simple all you need to do is write your variable name such as red var and inside parentheses you give it an initial value which this one we're going to be passing it in a now whenever you have multiple variables you want to set equal to you know the initial value you just separate them with a comma it's basically just like a list so our next variable is Const I was a constable and this one is going to be equal to B and what people sometimes like to do is put their variables on new lines but it really doesn't matter and another thing make sure that you don't put a semicolon at the end of this these aren't statements it's just a list it knows when you're done because the body is going to begin so basically start with a colon and make a list using the syntax variable value if you have another one separated with a comma variable value so I know it's really weird syntax but what this is going to do is we're going to be creating a constructor that takes two values and it's going to be setting them equal to a regular variable and constant variable and like I said before whenever you have a constant variable in your class this is how you need to do it of course we can set this variable equal to you know initialize it like we have before but you know we might as well use this list since we're you know learning this tutorial so now let's just go ahead and make another function avoid print just to print this stuff out on the screen so void okay there void sally print and all this is going to do is be like see out regular ver is and then just put reg var and then put constant variable is : Const VAR just like that and now let's go ahead and and that line and you guys can't even see a you guys still can't see there we go em line definitely sped that wrong and that line so now I'm just going to print out our regular variable is 10 and our constant variable is 20 or something stupid like that as long as I spelled this very let me just double check alright we should be good to go so now all we need to do is create an object in our main so let's go ahead and create a Sally object just name it s oh and remember this is a constructor so it's going to take two parameters just make like three and eighty-seven two random numbers just make sure they're integers and now as soon as we created that constructor it's going to take three and assign it to our regular variable and it's going to take 87 and assign it to our constant variable so now reg var equals three cos Phi R equals 87 so now when we call that print method and let me just I don't like typing stuff on the first line for some reason um s Oh dot print it should print that out unless I forgot a semicolon or something so let's go ahead and see and check it out regular variable is three constant variable is 87 mmm my spelling right there that actually does spell variable well I'm close enough so anyways one last time here is what we did we had a constant variable in our class this pesky little thing right here so whenever we have a constant variable in our class we can't initialize it like before we need to initialize it in a special way and that's through the use of member initializers whenever you want to create a member initializer list and basically this is just a fancy term for setting your variables equal to values you need to make a list in between your parameters and the body of your constructor and make sure whenever you're making that list to start with the : that tells c++ you're going to start making a mem list and just use this in text and don't forget to separate each variable with a comma and then of course whenever you create your object you need to pass it in the two parameters that need it because right here it said it asks for two parameters and then later on we can just use those variables in any old function just the print amount like regular variables blank constant variable is blank and then actually I got inside shrek you guys not have this function works actually I want to ask you guys this now I'm thinking about it is there a way to a like word wrap because like whenever I'm working with this you see I was going off the screen um let me know if there's a way to automatically word wrap so you guys well I guess I'll just scroll from now on I don't like my lines of code on new lines anyway so forget that like the last 30 seconds of this tutorial but anyways now that you guys know how member initializers work um yeah I'm just going to quit this tutorial now so thank you guys watching don't forget subscribe and I'll see you guys in the next video alright guys welcome to your 46 C++ tutorial and this tutorial might be a little longer than normal I might even have to split it up into two tutorials because I'm going to be talking about a subject called composition and I'm going to need to build a few classes so anyways composition is the idea that you know whenever you build a class it has members aka variables and usually a class just has some regular functions in it and some regular integer variables maybe a couple string variables well aside from just functions and regular variables a class can also have objects of another class as its member so you can stick objects inside classes as well so you know like whenever we created an object we always created it in main right here well you can actually have it inside other classes so let's go ahead and take a look at that and again composition is what it's called so the first thing we need to do is create a couple new classes so file new class I know you can't see that but I already showed you guys before so what I'm going to be doing is I'm going to be creating one class called birthday and that's pretty much just going to be storing a birthday which would be mine like twelve 2886 that's its only job so go ahead and create that and go ahead and press yes and okay so now we have a blank birthday class with nothing in it except you know the template so now what I want to do is build yet another class so file new class and I'm going to name this class people now go ahead and uncheck that and go ahead and press create and of course yeah I want to add it to my project and go ahead and whatever that thing said so what I'm going to be doing is every single person who's live has a birthday so wouldn't it be cool if inside this people class we can store a birthday or a date as one of its members so I'm basically going to be taking an object from a birthday class and storing it inside the people class and then running the main program for main so let's go ahead and get started first so in your birthday header file go ahead and delete protected because I didn't teach you guys that yet but in our private we're going to have three private variables in month which was the month of the birthday and and I said int in day and int year so that's man I cannot talk I keep saying for some reason anyways this birthday class has three variables it has a month a day in a year and what we're going to be doing is in can in our constructor we're going to be passing it in that information so let's just go ahead and pass in M for men and D for day and int Y for Year so we're going to go ahead and set the birthday whenever we create the object so now it's going to have one more function in it and that's void print dates and all this is going to do is print out the birthday on the screen simple enough so now let's go over to birthday CPP and it already includes birthday header but we already know that we need to include this stuff as well so go ahead and copy this and paste it right under here so now it includes everything we need it to include so of course the first thing we do is delete this comment because I hate comments and in our birthday constructor remember it takes three pieces of information a month a day in the year so let's go ahead and just actually steal this from over here copy that and paste it right in there so now it has three pieces of information that we passed in a month a day in the year so what we can do is use those values the set equal to the variables we needed we have a month variable add a variable in a year variable and all of those variables need a value so go ahead and for month set equal to the value passed in 4m four-day set equal to the value passed in 4d and for a year set equal to the value you passed in for y so as you can see now whenever we pass in our three pieces of information it sets em to month B for day white a year and this is going to be 12 equals month 28 equals day in 1986 equals year because that's when I was born so that's what I'm doing so aside from that we already know that we have to create this one extra function called print date and now this function does is print a date out on the screen so let's go ahead and make that right now void birthday print date it already knows that we need it and of course it doesn't take any parameters and all it does is print out something on the screen so C out month day and year and well might as well go ahead and add a end line for that so what it's going to do is print out the month slash day slash year slash and I know that this is formats kind of weird I think it's different in England and Great Britain but for those of you overseas yeah this is how we do things here in America we also measure like links with twelve instead of ten so yeah that makes it a whole lot easier like 12 inches in a foot who the heck decided there should be 12 inches in a foot is that it just you know 1010 would make things a lot easier but you know we have two stupid American system over here but anyways there's my little rant for the day now I can go ahead and work in my other class so after we're done working with birthday class and check it out we go ahead and we made everything here and everything here we are done with it let's hop over to our people class and the first thing that we need to do is include a couple of things um whenever I'm making a excuse me a people object I'm going to be giving it a name like Bucky Roberts so since we're going to be passing it in a name we need to be able to work with strings so include string and that will include the string class and aside from that we also need to include this birthday header file so go ahead and copy and paste and the reason we need to include this birthday header file is because as one of the members aside from just regular variables we're also going to be storing a birthday object in this class so if we don't have this birthday header file it's it would think we're just trying to make a weird variable or something and we'll get a error so that's why we need to include the birthday header file and aside from that we need the using namespace standard to get all our standard uh where you have people had her there you go all our standard crap so let's go ahead and start working on the people class so the very first thing why I should probably tell you guys is what information is going to be in this class well as I said before everyone has a name and everyone has a birthday so go ahead and put string name and go ahead and as a birthday we're going to go ahead and use a birthday object as a member of this class so whenever you want to use an object of another class inside this class you go ahead and first type the class name birthday and then you go ahead and give it a variable like date of birth so now this class people H every person in this class is going to have a name and a date of birth but we're not just going to pass it in the date of birth we're going to pass it in a date of birth object pretty cool huh so aside from that um we might as well go ahead and we're going to be passing in the constructor so we're just going to pass the name in is variable X and we're going to pass the birthday in as a birthday object so we'll call it Bo so whatever name we pass it in for X is going to set equal to name and whatever birthday object we pass in a Bo it's going to set it equal to the date of birth pretty cool huh so now let's hop over to people without CPP and you know I think I'm going to wait to do this until my next tutorial because this one's getting kind of long and I hate long video files they always mess up if they get too long so um in the next tutorial I'm going to show you guys how to write your people that CPP class and also how to tie everything together in main so the program works fine and smooth so thank you guys for watching that's all you get for now so hopefully I'll see you guys in next tutorial alright guys welcome back to your 47th C++ tutorial and this tutorial is just a continuation from the last oriole so what we did in the last tutorial is we pretty much we're working on the people h header file and now we're going to hop over to the people dot cpp to start actually building our functions but now that I think about let's go ahead and have hop back over to the people header file and aside from just the constructor let's go ahead and build another function just so we can print it out it will make everything a lot easier to see so let's go ahead and make a function called what was of this one called I want to make sure I don't name the same thing this one is called print date so we'll call this one print info I guess so print info so this is pretty much going to create our object and this is going to print out the information simple enough so now that we have this people class created in our constructor we said it was going to take two things every person needs two pieces of information a name and a birthday so what we need to do is we need to assign the name that they passed in and the birthday that the pass then to the private variables name and date of birth so in order to do that what we need to use is a member initializer list anytime you're working with um a class inside of another class you need to use a member initializer list so go ahead and remember don't put it inside your body right here you put it between your parameters in your body and again all a member initializer list is it's basically setting name equal to X and it's going to set the variable date of birth equal to Oh would we pass in Bo so Bo and also remember that you don't put a semicolon at the end of this it already knows it's done because the body will start so that's all we need to do for this right here so again we're going to be passing in two pieces of information we're going to be passing in a string and then a birthday object it's going to take that string and set it equal to name and it's going to tape that birthday object and set it equal to the day of birth so now this class has a name and now it has a birthday object that you can use so let's take the information and we can use that whenever we're building this other function print info so let's go ahead and um yeah I guess I don't need to do anything before that so let's go ahead and put void people print info and of course this print info doesn't take any information but it's just going to print something out on the screen so what it's going to do is see out your name variable which would be Bucky Roberts and then go ahead and write something like was born on and then make sure you don't end the line because I want all this to be on one line and then after this in order to print that date remember we have a function inside our birthday class that prints the date right here and we already passed in a birthday object inside this class so now this class has access to the birthday functions so we can go ahead and use this date of birth object right here that we created in order to use this print date function so let's go ahead and just write date of birth right there dot print date pretty cool huh so now whenever we print the info it's basically going to say Bucky Roberts excuse me Bucky Roberts was born on twelve 2886 pretty cool huh so now let's go over oh wait a minute I almost forgot to do this we need to include a bunch of stuff inside this people class um I'll talk you guys through it the first thing we need to include is our iostream and STD because you know we need to include those basically in every class and aside from that we also need to include this birthday header right here and the reason we need to do that is because whenever basically whenever you're working with another class you need to include the header so yeah I definitely just messed that up accidentally highlighted something so one more time okay let's not copy and paste it or in spots this time all right so let's go ahead and in our main CPP um everything looks good go so far actually what we need to do is since we're going to be working with birthday objects and people objects in this one we need to include include those headers as well so go ahead and grab this and include it right there and go ahead and grab this and include it right there so basically you see whenever you're working with the object you need to include it simple enough so check this out since the people class in order to create an object you need a birthday object whenever we run our main we need to create that birthday object first so remember in our birthday object when we first created our object needs three pieces of information a month a day in the year so let's go ahead and create a birthday object if I spell write birthday and we'll just name it birth object and then these those three pieces of information a month a day and a year so now we have a birthday object created called birth object and this birthday object pretty much took month day and year and set equal to twelve 2886 so now we can go ahead and create a people object people I'm just going to name mine Bucky Roberts and you're saying all right well what information does the people class need well whenever we create a people object it needs a string as the name and it needs a birthday object right there so first let's give it a name Bucky the King and the second piece of information it needed was a birthday object well it just so happens that we created one up here so let's go ahead and pass that in right there so after this what we need to do is might as well just print out the info right here so remember in the people class we had a function called print info and it just printed out the name and the birthday so go ahead and type your object named Bucky Roberts dot print info and remember it doesn't take any parameters and let's run this and see how many errors I got one so hold on once and I see what's going on all right see this up whenever we create this constructor we forgot to pass it in the parameters so just go ahead and copy these parameters copy and paste so hopefully that's the only errors we got and it looks good go so Bucky the King was born on 12 28 1986 works awesome so let me talk you guys through one last time what we did we just created a basic birthday class and this birthday class had three variables a month a day in a year so whenever we created a birthday object it took that month day in a year and assigned it to the three birthday variables month day in a year so we got the birthday class taken care of and then we decided to build another people class now the people class whenever you built a person and need the two pieces of information and needed a string which we gave it Bucky the King and it needed a birthday object so when for example whenever we had a birthday object right here we could pass it in second and what it did is in the main program it took that name and set it equal to the variable name and it took the birthday object and set it equal to the object date of birth so that basically gave us access to the birthday class so from there we were able to use data birth and the function in the birthday class to print out the birthday so basically whenever I run this this is a function from the people class and this is actually a function from the birthday class we just tied them together in one function right here pretty cool so that is basically what our composition is compositions basically using other classes inside your class using objects of other classes inside your class um that's all I'm going to go over for composition now hopefully you guys understand if you don't definitely go check out my forum and just type in whatever question you have and a ton of people are willing to help you but for now that's all I have for you guys this is a pretty long tutorial so go take a break go grab a milkshake or some and when you're done you're ready to move on to the next tutorial so thank you guys for watching don't forget to subscribe and I'll see you guys in the next video welcome back I steer 48th C++ tutorial and in this tutorial I'm going to be going over the keyword friend so basically every class can have friends and a friend of the class is something that's totally separate from the class but it still has access to the stuff inside your class like your variables and your functions so in other words if a class wanted to have a function it can make that function its friend and now that function had access to the variables and the functions inside the class pretty cool huh so let's go ahead and take a look at it so the first thing we need is a class and I'm going to name this class stank fist so let's go ahead and make our class right now the first thing I like to do is get everything set up so public and private so this class is going to have one private variable and int stinkie variable so now the only thing that has access to this thinkI variable is whatever is already inside this class so first of all let's go ahead and build a constructor for this stank fist and all this constructor is going to do is take that stinky variable and set it equal to zero so now as soon as you create a stink fist object and make sure I capitalized that consistency on my fist it's going to take this stinky variable and set it equal to zero simple enough so now what we need to do is we need to build a function so let's go ahead and build a function outside actually let's go ahead and make it right here so in order to make a function your friend the very first thing you need to do is prototype it inside your class so go ahead and put void one name this function stinkies friend and we'll go ahead and as a parameter it's going to take a stink fist object so stank fist and we'll just name this object s fo4 stink fist object so as a parameter it's going to take an object of this class so we're saying all right so that's all you do in order to make it your friend prototype inside your class one know in order to make this function a friend of this class before the prototype you need to type the keyword friend now this function has access to everything inside this class because it's its friend so now when we go ahead and copy this and paste it and create it we can use the stinkface object to access all the stuff inside the stink fist class pretty cool so first of all let's go ahead and change this stinky variable equal to something so using our stink fist object let's go ahead and access the stinky variable and set equal to 99 or something different than zero and now let's go ahead and just print it out on the screen see out SFO stinky variable and lime so basically what this does is even though there is a function right here you can see that it's totally different totally outside this class but since this class said you know what I trust this function it's my friend now this function has access to the stuff inside the class such as stinky variable and another thing I want to point out before I go on a class has to give away its friendship for example this function and this function can't demand to be friends with this class that's why you don't have the friend keyword right before it this class needs to give away its friendship other places just can't take it it's kind of like real life you can't make someone be your friend they have to accept you into being your friend make sense trust me I tried it didn't work out so well so let's go ahead and now that we got everything set up we can begin using this in main so our main what we need to do first is create a stink fist object so stink fist and I'm just going to name my object Bob and now we can use that Stinky's friend function right here and of course this function takes a stink fist object as its parameter so let's go ahead and as this parameter type in Bob and now we'll go ahead and run it and check it out as long as I didn't forget anything it should print out 99 pretty cool home so even though we were using this function and this function was outside this class it was able to access the stinky variable and print it out on the screen pretty cool huh so basically to recap one last time we wanted to build a function that can access this class but we didn't want to put it inside the class itself so instead what we decided to do was make this function a friend of the class now whenever this function tried to use the variables and functions inside of this class it was able to because this class said you know what you're pretty cool you can be my friend so then we made a function that took a stank fist parameter as its object so the first thing we need to do is create a stink fist object and we pass it in as its parameter and then ahead access the distinct fist class so that is basically the UM I don't know the lesson behind this tutorial whenever a class wants something to be its friend it can access the members of that class and aside from that a class has to give away its friendship other functions can't just demand to be friends with it it has to give it to them so there you go that's what friend means and that's why it's useful again this is a real simple example but later on I'll show you guys how it's really useful so just stick around and you'll see so thank you guys for watching don't forget subscribe and I'll see you guys in the next tutorial what is going on guys it's bucky and welcome back to your 49th C++ tutorial and in this tutorial I'm going to be talking to you guys about the this keyword but before I get into that let me tell you guys I'm sorry it's been a couple days since I made a tutorial but I had to upload 200 PHP videos to YouTube ND guys have any idea how long it takes to upload 200 videos to YouTube quite a while so anyways that's my excuse so now we can get back into C++ so let's go ahead and for this example I'm going to be making a new class because if I put it all in the same file it's going to get a little clustered so I'm going to name my class Hannah and actually I already messed up yes okay I actually made a Deconstructor and I didn't want to so let's go ahead and just delete that right there and now we can get coding our project so let's go ahead and first let's do a couple housekeeping things take this hand eh and paste it in here and now I'm going to take this and paste in here so basically your dot cpp files see this one and this one should basically look the same at the very beginning and what i also like to do is get rid of this protected crap right there because we didn't learn that yet so you know no use using it so basically what this hannah class is going to do is it's going to have a private variable I'll just name that int H now whenever we create an object we're going to pass in a value and integer value and all that's going to do is you know say we pass in 20 it's going to set H equal to 20 so that's all we're doing in the constructor and then we have another method to print out the H variable on the screen so we'll name that print crap because that's my favorite name for a function if you couldn't tell already so basically what we're doing is we have a variable called H and we're going to print it out on the screen and you're saying alright then what the heck's the point of the story well I'm going to be printing out this variable in three different types of ways the first way is normal like we talked about before and the two different ways are using the this keyword now we don't know what those mean yet so that's why I need to watch this tutorial so now that I got you hooked and anxious let's go ahead and start coding this constructor so again as I talked about we are going to pass it in a variable and X oh I mean I'm we're going to be passing in a value there we go I got a little tongue-twisted and we're going to set the variable H equal to that value so you say we pass it in 66 it's going to take H and set equal to 66 simple enough so now let's go ahead and start coding our print crap method right here so let's go ahead and make void an a print crap and it's not going to take any parameters like I said it's just going to print some crap out on the screen and let's go ahead and make a template first and in line so this is what I do whenever I code by myself I probably shouldn't do this whenever I'm making tutorials but I basically make a shell of whatever I can and then fill in the blanks so the first thing we were going to want to print out is what h equals and it's just going to be you know H so say we passed in so say H is equal to 99 it's just going to print out H equals 99 on the screen so now let's get in the good stuff the meat of this tutorial and that's the this keyword now I'm actually going to be doing this story a little bit different than before in order to teach you guys the full concept I'm actually going to make a my entire program first and then walk you guys through I usually you know um walk you guys through what I'm doing as I'm typing but it's going to be easier to understand if I actually make my whole program first so this H equals this H this is going to pronounce me you guys will know by the end of this tutorial and actually this weird kind of H is also gone let me add my equal signs equal signs I know you guys are anxious to see what this all is but I'm not going to tell you guys yet so now we're basically printing out H in three different kinds of ways this way this way and this way get it this way it's a cheap little joke but anyways let's go ahead and now we have to create an object to actually call those functions so Hana H oh and let's just pass it in like 23 or something like that so first what this is going to do is it's going to take the value of 23 and set it equal to the variable H so when everyone's program is going to print out 23 23 23 so now after that we of course need to call print crap right like that so let's go ahead and build and run this and see if I got any errors which I did because I forgot a semicolon let's run it again and check it out H equals 23 make sense we already knew that now this arrow H equals 23 all right oh we're not exactly sure what that means and whenever we use parentheses star this that H that equals 23 2 so basically we can see that these are three different ways of printing out the same variable so we already know that whenever you print out on a private variable we can just use that private variable name and it prints out the value so we already know what that one does from the you know the last 80 tutorials so let's go ahead and skip right on down to this one and that's this arrow H well remember in tutorial like 42 or something I told you guys whenever you use the arrow it means you're going to be working with a pointer so that's kind of weird so that means this is a pointer well yes it does in a C++ program whenever you use the word this it's actually a keyword that identifies a special type of pointer the key word this stores the address of the current object that you're working with it sounds kind of weird huh so that's why action needed to build this entire program first because I needed to build an object and the object we're currently working with is H Oh so whenever we use that object H oh it took the address of it and by the way H o is stored somewhere on our computer and memory deep down you know some weird location but it took that location and it stored it in the key word this so now that this key word identifies a special type of pointer like I said that stores the address of H oh if we made another object called Bo it would then hold the address of Bo so whatever object you're working with it's going to take that address and store it in a pointer called this so basically it's saying the address of H Oh use that object in that object has a variable H so that's why this and this are basically the same thing and you're saying all right so if they're the same thing why does this work and why does this work this whenever you print out H it's just implied that whenever you're working whenever you're here let me say it like this whenever you print out this variable right here c++ assumes that you're working with a curved object whenever you print out like this way using Heuer this it's basically explicitly telling c++ so this is usually you know just assuming that you're working with the correct but this is explicitly telling c++ you're working with this current object it just you know a different way to do things but actually this keyword is pretty important I'm going to show you guys why it's actually useful aside from just printing out variables so basically what I want to stress you guys in this soil is whenever you use the keyword this it stores it as a special type of pointer and that pointer stores the address of the current object in this case was H oh so this is saying the address of H Oh get that object and that object has a variable H and H is equal to what do we set equal to 23 so that's why this prints out 23 now that I confuse these guys let's move on to this one down here now this is basically a different way to access the object the this with a weird pointer and then surrounded by parentheses this is called dereferencing a pointer and what this means is it's literally taking the memory location of the current object which is you know some long hexadecimal x 0 j 42 yada yada and it's taking that memory location of the current object and calling the variables value right there so this is basically saying alright whatever current object we're working with what is h0 that h0 has a variable called h now print out the value of h in this you know just assumes we're working with h oh right here we're saying we're going to be using this keyword to talk about h oh and right here we're using the explicit memory location of the object h oh so this is basically implied explicit explicit just two different weird ways of doing it so now that i taught you guys that in the next store i'm going to show you guys why you would use the this keyword and you know it's not just something that you can use the show off that you know more about sleep plus plus it actually is useful in some programs so maybe the next tutorial will be a little bit more useful but for now that's all I got for you guys so hopefully I can fuse the eyes if you need some more information check out my website the new Boston comm and you can ask me a question there but for now thank you guys for watching and I'll see you guys in next door alright guys welcome back to your 50th C++ tutorial and I know in the last tutorial I told you guys I was going to be building a program using the this keyword but I was building it and I noticed that there was a lot of concepts I didn't teach you guys so we're going to have to come back that after I taught you guys a couple new concepts so we'll get back to that but for now I want to talk to you guys about something called operator overloading now operator overloading is a weird feature with C++ well operator overloading is is it allows you to use C++ operators like you know plus and multiply and it allows you to take these operators and change the way that they're used so for example maybe you have a class and you want to add two objects together well how the heck does C++ know how to add your two custom objects together well that way you can use operator overloading to specify what you want this operator to do so what I did already is I made a new class called Sally and I also include the Sally header in here and I included an IO Sriman namespace in here so now my dot CPP files look the same just to save this tutorial some time so now let's go ahead and get into the coding so let's go ahead in the sadi sally header file and notice that i took out both private and protected because we're just going to make everything in public it's going to make everything a whole lot easier so the Sally class is going to have a couple things in it the first thing it's going to have is a variable called num and this is the only variable it's going to have um it just needs a variable pretend this is like Sally's age or something I just named it num because it's easier to work with now let's go ahead and create two constructors the first constructor is pretty much just going to be empty constructor we're going to be building a sally object and whenever we don't pass any parameters to it it's just going to create a blank sally object and we're also going to be creating another constructor and whenever we create a Sally object and we pass an integer into it what I want to do is well let me go ahead I guess can code this right now whenever we create a Sally object and we pass an integer into it called like integer a or something what this is going to do is I like it right up there what this is going to do is take that number T and set it equal to a so we're going to create Sally objects in two ways a blank Sally object or a Sally object that already has a number simple enough so now let's get to the last thing in the Sally class and that is you know what I've been talking to you guys about this thing called operator overloading now again like I said operator overloading allows you to use C++ operators in a special way inside your classes so in order to use an overloaded operator you need to make a function and you need to give it a special name so whenever you build a function in C++ you need to first give it a return type now this function is actually going to return a sally object so go ahead and type a sally right there and now you have to name your function and you have to name it this whenever you're using an overloaded operator you have to start it with the named operator and then right after it you write what operator do you want to overload and this can be multiplied divided but we're going to be overloading the addition operator and what this is going to do is take two of these number properties and add them together so let's go ahead and write operator plus this is the name of our function now and this is also going to take a parameter what this function is going to do is it's going to take one Sally objects number and add another Sally objects number to it so we're going to need to pass it in another Sally object to add to it so let's go ahead and call it like um Sally well all we have to put is that Sally so now let's go ahead and build the function itself so let's go hop over to Sally dot CPP and let me make sure it I forget any semicolon looks good so now let's go ahead over to Sally about CPP and start building this function again the very first thing you write is their return type this is like void and well we're returning a Sally object so go ahead and write Sally right there and now we have to go ahead and write what class are we working with Sally what's the name of our function and remember that's operator plus since we're overloading the plus sign and what parameter does it takes well it takes a Sally parameter and just name this variable like ASO for another Sally object so now what we want to do is this we're going to be returning a brand-new Sally object so let's go ahead and make a new Sally object right now Sally and name this object brand-new simple enough so now let's go ahead and add the number property to this brand-new object because we created a brand new object but it doesn't have anything for its number property right here so let's go ahead and put brand-new dot num and what do we want to set this equal to well what we want to set equal to is the current objects number value plus another Sally objects number value plus another sali objects number value so basically we're going to have to Sally objects already we're going to have a Sally object that say has a number of 20 and another Sally object that has a number of 30 and whenever we create the brand new number it's going to have a value of 50 so that's where we're going to be returning the brand-new Sally object so in order to do that all you do is this return brand-new just like that and what this is going to is return the brand-new Sally object so basically we're going to be calling this on a Sally object that already exists and what it's going to do is this line is going to create a brand new Sally object right here we give a number value to the brand new Sally object and right here we're just returning that brand new Sally object simple enough so let's go ahead and well I guess now we can hop over to main and I can actually you know show you guys what's going on so the first thing we need is two already existing Sally objects with the number property that we can add together so Sally well we call this object a and we'll give it a value of like 34 now we need another one Sally B and we'll give this value 21 now we need a blank one because whenever we call this value remember it doesn't have a number property yet so that's what we're going to be giving it so let's go ahead and create a blank Sally object with a C and now all we need to do is this you might be thinking are a whenever I wanted to before like give a number property to the C value I would do something like C equals a dot add and then you would add B to that and I mean what that would do is whenever you wanted to add a number property to see it would take a and add B get some integer and add it to the property of C right there well with this overloaded operator you don't have to do that anymore here's we need to do C equals a plus B in that way whenever we use the plus sign C++ already knows that we have a special meaning for it right here so whenever it sees the plus sign call it on one of these objects it's going to know to run this function right here so let's go ahead and run this in now that we use that plus sign the C object has a number operty so let's go ahead and see out um c dot num and then let's go ahead and end that line and let me go ahead and run this real quick and I'll show you guys that it says 55 so what it did is basically this it took this number value 34 added this number value 21 it gave us 55 and through the use of our overloaded operator that's where we got the Sally num so let me talk you guys through one last time what's going on maybe this will clear things up for you in our very first line of code we created a Sally object and then um had a value of 34 so we know whenever we created a Sally object and we passed in an integer then assign that integer to the property of num so we have a Sally object in a Sally object is num 34b Sally object is num 21 and then we created a see Sally object and remember whenever we created a Sally object that we didn't pass in a parameter it just created a blank Sally object right here so we said all right with our blank Sally object we want to use a plus B so set all right I know this plus since you're trying to do something weird I know that you're trying to use this overloaded operator so it said RAC goes a plus B that means you're trying to use the Sallee object with this function right now so what it did is it took the current object which was a right there and this B was treated as the parameter another Sallee object so what it did it was it took the current object's number which was 34 it added another Sallee objects number which was 21 and it returned a brand new sally object with 55 is as its number so as its returned value we said equal to C so C now equals a brand new sally object with 55 as its number so that way whenever we printed out our brand new sally object with its new number that's why you printed out 55 on the screen right there so again like I said operator overloading is a little weird because it basically takes your plus sign and you know you don't have to use a function name anymore so instead of this it pretty much changes that all into a plus sign so I know it's kind of a weird syntax at first and to be honest I don't use it a whole lot in my programming so if that gives you confidence that you're probably not going to be seeing this a whole lot then you know you can relax but I just want to give you guys the idea of what operator operator overloading is because you know whenever you're at a job and people are talking about it you don't get lost or whatever so that's what it is but you won't be seeing it all too much in my programs so now that you guys understand the concept of it thank you guys for watching don't forget subscribing you're probably going to have to re-watch this video a couple times and do some examples of your own and if you have any questions don't forget to check out my form the New Boston comm slash for them and hopefully I can answer for you so anyways one last time thank you guys for watching don't forget to subscribe and I'll see you guys later alright guys welcome to your 52nd C++ tutorial and in this tutorial I'm going to be talking about something called inheritance now inheritance is a topic that confuses a lot of people but I'm going to be giving you guys a really simple explanation and showing you guys a really simple example of what inheritance is now inheritance is the idea that you can inherit things from another class for example say you have a class that has a couple functions in it and a couple variables in it and you wanted to make a new class that also had the same functions and variables in it well instead of you know copying them all and pasting them all into your new class you can just inherit from the other class and whenever you inherit from another class you get all the stuff you get all the functions and variables so let's go ahead and make two classes file new class I'm going to make one class named mother and this class is going to have a couple things in it well it's going to have a function in it for the sake of this tutorial so let's go ahead and create this add it to project and I'll press ok and now I'm going to create a new class called a daughter now what the daughter is going to do is inherit this stuff from the mother so go ahead and press create yes and okay so the first thing we need to do is go to our dot CPP copy this paste inner main and also go to our daughter copy this paste in our main and then copy all this and paste it and paste it so now all our dot CPP s look the same that's why I like doing all my tutorials so let's go ahead and our mother header and actually in both our header files take out protected and private because um I didn't tell you guys what those mean right now so let's forget about it for now they're actually pretty important when we're talking about inheritance but like I said in this story we'll just want to give you guys a really simple example so before I go on let me give you guys the technical terms see we're going to be inheriting all the stuff for a mother and we're going to be putting it in the daughter class but now the technical terms if you're on a test or if you're working for a job or something whenever you inherit from a class this main class that you're inheriting from is called the base class so in this example mother is going to be the base class now the stuff that does the inheriting the daughter that gets the stuff this is called the derived class so the base class is the class with all the stuff in it and the class that is going to get all the stuff is called the derived class so let's go on and start typing our example so let's go ahead and throw one function into the mother class and we'll just you know void say name so this is the Robert's family we're dealing with so let's go ahead and build this function right here right here all right we don't have anything in the constructor because the constructor is annoying now let's go ahead and build this void mother say name function and all this function is going to do is see out I am a Roberts because that's what my mom shouts all the time and she doesn't know how to spell so that's why I have to add some typos in there so now if we go ahead in our main CPP we can build an object called like mother named it mom and what mom can do is say name and of course it would say I am Roberts on the screen and say you wanted to build another object a daughter object and we'll name this Tina and you wanted Tina to have that same function because I mean she's Roberts - she should be able to say it well right now whenever we build it it doesn't work because Tina doesn't have that function only the mom does so saying RA I know in this case go ahead and copy this put in the daughter header then copy all this crap put it in the daughter CPP and it should work fine well yes you can do that and it'll work fine but I got an easier way to do things and that is through inheritance now whenever you want to use inheritance all you have to do is this in the header file whatever class you want to inherit the stuff from right after the class name put a colon and then right after this write the word public and then write the class you want to inherit from which is mother now we're going to be talking about this keyword why I put public right there basically it means um all this public stuff is going to be public in here but we'll be talking about later there's a couple of weird things but you know just put public for now so basically what I'm saying to C++ is this alright in my daughter class include all the stuff from the mother class so what it's going to do is go over to this mother class go ahead and grab this function right here it's not going to grab the constructor that's another silly role but it's going to grab any public variables and any public functions and right now we only have one public function in that same name and it's going to throw it inside the stoddard class so now this daughter class is in hairatan from the mother class so now check it out even though we didn't explicitly write that same name function in here it inherited it so it's there even though we can't see it so now let's say we want to take away this part right here and we try to run this we don't get any errors and now the daughter is able to use that same name function so again what inheritance is is this whenever you have a class and you want to inherit the crap from another class you can write a colon and then public and then that name of the class and what this does is it takes everything from this class and it sticks it in this class so this is called the base class and this is called the derived class whenever you inherit everything from the base class gets thrown in the derived class so now even though we can't see the same name function it's there so that way whenever we created a daughter object the daughter object was able to use the mothers functions even though it wasn't explicitly written in the documentation or dot CPP file whatever the heck you want to call it so that's why we were able to run this daughter object and use the same name function on that so that's what inheritance is it's basically inheriting stuff from another class but you know how I said that there are a couple weird rules like you needed this public thing and whenever you inherited it grabbed all the stuff from this mother class and throw into the daughter class well that's not exactly true I don't want to say I lie to you guys but for the sake of this tutorial I just wanted to make a simple arm there are a couple weird exceptions in whenever you inherit from another class it doesn't actually grab everything Aronian grabs a couple things and also you need this public keyword or out some weird stuff will happen if you try to use protected or private and that's what I'm probably going to be talking to you guys about in the upcoming tutorials but for now what you have to remember is this inheritance is basically grabbing another class and throwing all the stuff in to a derived class so this is called the base class this is called the derived class that's what inheritance is pretty simple huh you inherit this stuff from another class that's all it is so now that I talked about that we're ready to move on to next tutorial so thank you guys for watching don't forget to subscribe hopefully you understand the concept of inheritance if you don't watch the video again and I will see in the next tutorial alright guys welcome to your 53rd C++ tutorial and if you've been following these stories you know that I've been gone for like a week and I might be kind of rusty with C++ but uh I'll get the hang of it I've actually been planning something and I'm not going to tell you guys what it is but I will say that is awesome and it's going to happen in about a month so that's Sarah a little teaser so now it's good back into C++ let me get my head straight actually just open this program so I think what I was supposed to teach next was about protected because that's what's looking like so I think in the less story I just covered basic inheritance I probably should have you know watched that video watch the last video before I started doing this one but who has time for that so let's go ahead and talked about what protected member is you know whenever I first made a class like this mother class right here automatically it's stuck in public protected and private those three variables or mean those three code words and you're supposed to put all your functions and variables in there and I usually just deleted private or protected and I'm like don't worry about that we'll worry about this later well now is the time to worry about it so let's go ahead and in our mother class just throw in those keywords again so public we already know what this does let's go ahead and make a variable for each one so we already know what public means um anywhere inside this class has access to this stuff and also outside this class can also access this stuff whenever you write something in public it pretty much means anywhere in the program you can access this crap so we'll just name it public v4 public variable so now let's go ahead and talk about protected well before we talk about protected let's talk about private because I mean might as well get out of the way the things you know already we all do you know that whenever we make something like a private variable that this means that only inside this class has access to this variable for example if we want to go in another class or in this main.cpp class this class would not have access to these private variables and that's why we need to build methods inside this class that are public to access those private variables so basically what we know so far whenever we make something public any other file has access to it whenever we make something private only this file or only this class has access to it so saying all right this is a this is B so what the heck is this one is kind of like sitting in the middle is it like combination of both well yes it is listen very closely whenever you make something protected here is what it means anything inside the class has access to it just like public and just like private any friend has an access to it and remember we talked about friends earlier pretty much just saw out things outside the class that has access to stuff inside your class and also your base classes remember a derived class inherits from the base class right so any class that is inheriting from this class has access to it so if we were to make a private variable in this mother class and then the daughter class inherited everything from mother well it wouldn't inherit the private variables these private variables are still private to mother even though daughter inherited from mother daughter does not get these private variables daughter would in fact get public and protected so it would inherit these two but not private so that way you can kind of see it's a mix between public and private um it doesn't let anything inherit it like public and it doesn't just stay in this class like private it's kind of like it in between so I'll go ahead and make a protected variable protected V and I'll go ahead and show you guys an example so let's go ahead and build a function inside daughter and we'll just name this go ahead and make a public function of course public and we'll just name it like do something nice about that right and close enough so now let's go ahead and build this method right here and I keep thinking like I'm forgetting something but I guess it's just because I haven't programmed in a while so let's go ahead and put void daughter hopefully I'm doing this right all right and what was that oh do something and got it right there for me how nice so now we'll just go ahead and do this Oh actually I might as well do this one at a time this will probably show it to you very clearly so let's go ahead and before we even start coding this function right here let's go ahead and build a daughter object so daughter I think her name should be Tina that seems appropriate for this tutorial and Tina dots do something right like that so now hopefully when you run this nothing happens because nothing's in this function right now so let's go ahead and see just whether you have any errors right now nothing happens good so let's go ahead and do this let's say we want to access that public variable and which is like set equal to a number or something we just want to try and access it so let's go ahead and try to access that public variable and do something to like set equal to one or something stupid well we go ahead and run this and no errors so we know whenever we do that that we do indeed have access to the public variable and just a reminder this daughter class is inheriting everything from this mother class and that includes a public variable a protected variable and a private variable now we already know that daughter can access that public variable in this line of code right here so now let's try and step it up a notch now let's go ahead and try to access that protected variable protected V right there well if we go ahead and try and set this equal to you know two or something like that and we build and run it it works perfectly so therefore we can see that that excuse me the derived class can indeed access the protected members of the base class and remember mother is the base class daughter is the derived class whatever does the inheriting aka the daughter is the derived class the core class that has the crop we want to inherit from that's called the base class so now we know that we can indeed access public and protected members from the base class now let's go ahead and do something that we know we're not allowed to do and try to access a private variable and let's go ahead and try to set this equal to three and now we'll go ahead and try and build and run this and it says I'm Bucky I don't think so you know the rules you are not allowed to inherit private members so that's why we're getting an error whenever we try to inherit for a private variable so the concept behind this story is not to build a stupid program that does nothing but it's this whenever you're inheriting from a class you can inherit all the public stuff you can inherit all the protected stuff but you cannot inherit the private stuff so remember whenever you have a base class you're going to give this crap and you're going to give this crap but on you ank in this class biatch I met a crap that's embarrassing but I'm not going to redo the Storrow just because I mess up that one sentence okay got it all right so let's um you know that's enough of me talking for this story I think that's a I think you guys understand the concept by now basically at the heart of the story you can inherit everything except private variables I couldn't make this tutorial real short but I didn't so thank you guys for watching I don't forget to subscribe and by the way if you guys want a nice organized playlist um I did I don't really like doing them on YouTube because it's not really easy to organize that way but if you go to my website I have all my videos laid out can watch one right after the other from clicking a button everything is nice laid out in a nice playlist for you guys so thank you guys for watching don't forget subscribe and I'll see you guys in the next video alright guys welcome to your 54th tutorial and in this tutorial I want to talk to you guys about the derived class constructors and deconstructors basically I want to figure out this riddle whenever you have a constructor in addy constructor in the mother class does the daughter class also inherit that constructor well it inherits everything else so is that constructor and Deconstructor included well your short answer is no it does not inherit the constructor and D constructor from the mother class or does it I guess you're going to have to watch and find out so let's go ahead and first make a constructor and D constructor in the mother class so let's go ahead and remember in order to do that just create a function with the same name mother and tilde mother for the D constructor now let's go ahead and set this up and I guess we'll build the constructor first mother mother and all we're going to have this constructor do is like C out I am the mother constructor explanation point emphasis on that crap and now let's go ahead and do the same thing let's copy this because I'm lazy and remember dadier tilde so that's the D constructor and just write mother let's get rid of the IMD it's tacky she's a mom mother D constructor so now we have a mother class that has a successful constructor and D constructor so now whenever we create a mother object like mother MA it should build the object so and I messed up something right here some mother mother let's see what I messed up oh here it is right here and L you need that because end is not keyword so let's go ahead and run the skin and now whenever I create a mother object you can see that the object gets created I am the mother constructor and whenever the program comes to an end the object gets destroyed mother Deconstructor so our mother object works as expected I guess you could say whenever the object gets created this runs and whenever it gets destroyed this runs we already know what a constructor and B constructor does so now let's go ahead and build a daughter object now remember at the beginning of this tutorial I promised you guys that the mother constructor and the constructor even though the daughter is inheriting all the stuff from the mother I promised you guys that it is not inheriting the constructor and D constructor so let's go ahead and build the daughter object if I can type daughter and we'll just name this like Deena because that's a nice name so let's go ahead and build and run this and see what we get whoa whoa whoa Bucky Bucky I think you lied to me it said I'm the mother constructor I am the mother constructor Bucky you mofo you son of B you told me that the daughter is not inheriting the constructor from the mother class so why on earth would it run this constructor twice well let's go ahead and actually build a daughter constructor and we'll see exactly what's going on we'll see if I actually did lie or if I didn't so in order to build daughter constructor let's go ahead and build daughter parentheses and also tilde daughter for the whoa what the heck is that escape the heck is ahead I do not know how that got there anyways let's go ahead and do that and actually instead of having to copy this I'm just going to you guys should not do this by the way just close your eyes for this part and just going to change this to daughter and copy this always bad programming practice because you always usually mess up something but hopefully that should run just like that and now the mother class has its own unique constructor and D constructor and the daughter class has its own constrictor and D constructor so now whenever I run this you're saying alright so you lied me obviously the daughter did in fact inherit the moms constructor so now that it has its own construction and Deconstructor I should see just two constructors and 2d constructors run from the mom one from the kid so let's go ahead and build this in what the heck is this crap six things popping up all right Bucky you need to take a timeout and explain to me what's going on well in order to do that I'll make it real simple for you guys just comment this out right here and run this program again and now we see once we just built this one daughter object actually let me go ahead and take this out completely and now XS out and build it and run it again now we see that even we built even though we built one daughter object it's still running that mother constructor and the daughter constructor so what the heck is going on Bucky alright now let me take a timeout take a deep breath because I got some explaining to do when I told you at the beginning of this story that the daughter does not inherit the mother constructor I wasn't lying I was telling the truth even though the daughter is not inheriting the mother constructor the mother constructor still runs so basically here is how your program works whenever you start this program it says alright I have one daughter object that I need to make so the very first thing I'm going to do before I do any of my own crap in the starter class the very first thing this program is going to do is it's going to invoke the base classes constructor so it says alright daughter you have one base class called mother so let's go up to mother and we're going to end and we're going to invoke the mother constructor before we even do anything with the daughter so that's why the very first thing we did was invoke the mother's constructor and then after that we were able to invoke the daughters constructor so basically whenever you use a class it sets up all its base classes before it does anything on its own class so that's why whenever running the starter object it sets everything up on top of it before it you know did the daughter stuff and another thing I want to point out say you weren't only inheriting from a mother but say there was a grandmother and a great-grandmother and there was a huge hierarchy well it's still the same thing if that was the case then the great-grandmother would get done first and then the grandmother and then the mother and then the daughter basically the very top class is going to get done um the constructor is going to get finished executing first on the top most class and this is because like I said whenever you have a class that inherits from another class it needs to set up the class above it in order to make sure everything is going to work inside it so the daughter is going to say RA I need the mother in order to work and the mother is going to say alright I need the grandma in order to work and the grandmas going to say RA need the great-grandma in order to work and that's the very top so that's why the great-grandmother it would be set up first but in this case we only have a mother and a daughter a very simple explanation so that's why the mother gets set up first because in order for this daughter class to work the mother class needs to be working first so that is why the mother constructor gets called first like I said the daughter class isn't inheriting it's just setting it up so that's why this mother constructor gets ran simple enough so that's why the mother constructor gets ran and then the daughter constructor gets ran but then the daughter D constructor gets called first and then the mother D constructor that's kind of weird you're saying alright if we're going to set this class up first then you might as well destroy it first right but that's not the way it works it goes mother daughter daughter mother it's kind of gets sandwiched in there so here's what's happening with the rest of the program whenever an object gets destroyed and remember we only had one daughter object in this program then here's what happens whenever an object gets destroyed its Deconstructor gets called so Deena's Deconstructor got called first and whenever your program saw that this D constructor get called it sets off a chain of deconstructors the kid called after it so if there's were you know a huge family the daughter would get the daughter would die first and then the mother and then the grandma would die and then the great-grandmother so it gets kind of built in a reverse order then dies but that's how it works so basically one last time whenever you're first say you had an object like the daughter all of these spaced classes the topmost base class gets instantiated first it takes care of the uppermost class first because it needs every class needs class on top of it to work in order for that object work so that's why mother got called even though we weren't inheriting it we needed to set it up before a daughter could get set up now whenever this program ends the first thing to die is this daughter object and once this daughter dies is going to set off a chain of death throughout the family the mother is going to die then the gram is going to die then greg grandma's going to die then Osama bin Laden's going to die because that's what happened yesterday and that's what day it is in case you guys are watching this like three years in feature that's what date is today uh May third Osama bin Laden was declared dead yesterday or two days ago whenever they announced that so anyways I think I'll just in on that note because I'm getting way off topic now and I probably confuse the guys enough so I thank you guys for watching don't forget subscribe and again if you want to check out my tutorials and organized fashion check them out on my website they're all nice and laid out for you guys so thank you guys for watching don't forget subscribe now see eyes later what's going on guys it's Bucky and welcome to your 55th tutorial and in this story I'm going to be beginning to talk about something called polymorphism now polymorphism is a subject that gives a lot of students and a lot of people problems because whenever someone tries to explain it they make it really confusing so let me give you guys just a basic example um you know not through code or anything I just want to talk to you guys for a second so say you wanted to make a computer game and you know that your computer game you wanted to include a bunch of enemies like monsters and ninjas and you know just a bunch of different types of enemies well all of these enemies share the common function say they all had an attack function to try to attack you however they all attacked you in kind of different ways maybe the ninja threw a sigh at you and a monster tried to scare you from under your bed and you know all these different enemies even though they had the same function you know they worked a little bit different well will polymorphism allows you to do is it allows you to call that same attack function on many different objects and since all of these objects like ninjas and monsters since they're all enemies this is why it's valid so since they all inherit from the same class you can call attack on each different object and even though ninja has an attack and Monster has an attack even though you're calling the same function on different objects they all would know what to do they all know that they're supposed to attack you in some way so polymorphism basically allows you to do is use the same function and have many different outcomes so that's the basic idea behind polymorphism but there's actually a lot to understand so let's go ahead and get to it so let's go ahead and start making that computer game now so go ahead and make class and we'll name an enemy and don't forget put your semicolon at the end and now let's go ahead and let's say that we're going to have a ninja in a monster and they're each going to have an attack power how much you're going to hurt you so let's go ahead and well since we learn what protected is we can go ahead and you that and we'll put int attack power so now every enemy has an attack power so now let's of course make a function in order to set that attack power so we'll make it public of course and we'll just make it void set attack power and this is going to take one parameter of course some number and using that number we're going to set the attack power and again this attack power doesn't really mean anything it's just a made-up number so attack power equals a so we're going to pass it in like a value of ten and you know the ninjas attack power is 10 whatever the heck attacked by our means right so now let's go ahead and make another class let's go ahead and make class ninja and this ninja class is going to inherit from Public Enemy so all ninjas are enemies we already know that so now let's go ahead and add some things that are specific to only ninjas well in each of these classes let's go ahead and make an attack function so public void attack there we go and now what we can do is I guess I'll just throw everything on one line um this is the part that's going to be specific to the ninja class so right here we're saying all right we're going to have some ninjas but a ninja is still going to be enemy I mean the enemy's an enemy so whenever a ninja attack what I want them to do just see out on the screen um I am a ninja ninja chop and it'll be like - not ninja cob come on ninja chop and it will be like a - and then you write the attack power because remember since it's the enemy it has that attack power attribute that it inherited hopefully you guys watched my last couple tutorials and aren't like what the heck does inheritance mean and then just go ahead and that line right there so now we have a ninja class that has all this crap from enemy since it inherit from enemy and it also has its own specific attack function so whenever a ninja attacks is going to say I am a ninja ninja chop minus 10 like it did 10 damage to you or something so let's go ahead and copy this and we'll make another class right here we'll call this class and actually I'm about to scroll off the screen so let me just bump this up and we'll make you know this a monster class now a monster is also an enemy so you have two enemies you have a ninja and a monster however when a monster attack it says a monster must eat you explanation for explanation point it'll be like minus 25 or something like eating you doesn't kill you it only does 25 damage so basically what we have here is three classes we have an enemy class which is common to all enemies so all enemies are going to have an attack power however each specific enemy attacks in a specific way a ninja is going to chop you and a monster is going to eat you so let's go ahead and start coding and making all these objects so in our main right here let's go ahead and make a ninja object ninja and I'll just name this n and a monster object and I'll just name this M so you got a ninja and a monster and now what we need to do is we need to make two enemy objects so let me go ahead enemy and make a pointer and we'll just name this enemy one and we're going to set this equal to the address of our ninja object now before I go on let me say this because this ninja object is of type enemy remember all ninjas are indeed enemies all monsters are indeed enemies that's why we can do this that's why we can say the address equal to the pointer so anything that an enemy can do a ninja can do does that make sense they should and also anything an enemy can do a monster can do so let's go ahead and just I shouldn't do this you should never copy and paste because you always mess up stuff enemy 2 we'll set this equal to monster address so basically what we can do now is this we can use that enemy 1 object and remember whenever you're working with pointer functions you need that little arrow and you see it already pops up attack power so our program already knows that and any enemy object you can call attack power because even if it's a ninja a monster they all have an attack power so that's why this is valid so whenever you set your attack power to you know a ninja can do like 20 damage or 29 or whatever it already knows that it's supposed to apply this to the ninja object so even though we're setting it enemy attack power 29 it knows that indeed since it's pointing to the ninja object that means the ninjas attack power is 29 so basically before I go on because a ninja is a type of enemy this is valid this line of code right here anything that ninjas can do excuse me anything that enemy can do a ninja can do because a ninja is just a more specific type of enemy so every how should I says every enemy has an attack power so that's why we're able to do this every enemy has an attack power and the reason knows whose attack power to set is because it's a ninja object right here enemy 1 equals a ninja object so let's go ahead and just copy this again you should never copy you ladies and gentleman and we'll say enemy 2 which is the monster let's set this attack power equal to you know 99 or something stupid so now we can go ahead and with each of these objects we can call attack and it will give it their own custom text so and attack already filled in first and M attack so we kind of used a combination of you know two different classes using the general enemy class we set the attack power and then whenever attacks it's going to use that attack power like I'm a ninja ninja chop 29 so let's go ahead and run this and see if I forgot nice semicolons or anything and I did so hold on one second all I see what I did wrong what I did wrong is I actually just try setting the attack power and the method was called set attack power so let's go ahead and copy this and we'll set attack power to 29 and set attack power to 99 now if we go ahead and build around that there we go it says I am a ninja ninja chop - 29 and the reason at NU - 29 was be kind because of this line right here and whenever we set the enemy - which was an enemy object but it knows that it's supposed to be working with that monster object whenever he set that equal to set that tech power equal to 99 right there had to find it it knows that whenever the monster attacked it was supposed to have an attack power of 99 so that is basically how you can do that and I guess I'll see you guys later alright guys welcome back to your 56th C++ tutorial and in this tutorial we're going to be talking more about polymorphism because I know I kind of cut off the last tutorial abruptly and that's because I understood that I wasn't making a couple things clear so I wrote some comments here and read these line by line and hopefully they can make you understand the basics behind you know inheriting and using these pointers with different types of objects easier and also I wanted to stress one thing that you guys may not quite have understood now if we go up to you know the ninja class in the monster class you saw that each of these specific classes had a function called attack so a ninja could attack and a monster could attack however if we strode up to the enemy class where they both inherited from there was no attack function right in here so that is why we had to switch back to using the ninja in the monster attack after we set the attack power so that's why the enemy object see let me go ahead and like if enemy object was to try to attack you would get an error message because an enemy object can't attack because this enemy class has no attack only these specific classes do you see what I'm saying so that's why we could use the enemy object to set the attack power because every class inherited this attack power but we couldn't use those enemy objects to attack because only these specific classes can attack so saying alright Bucky that's uh I understand it now but it's still kind of you know a dumb way to program because first you make a ninja object and an enemy object then you use the enemy object here then you have to switch back to the ninja object right here well wouldn't it be nice if we could just have these enemy objects come on I keep it in that dumb plus sign what it'd be nice if we could just have these enemy objects attack as well that would make our lives a whole lot easier if we didn't have to switch back to this ninja in monster class if these enemy classes excuse me these enemies objects could just set the attack power attack move around to whatever an enemy needed to do we'll check it out guys that is the core concept behind polymorphism and it's going to make your programming life a whole lot easier so let me go ahead and I'm going to go ahead and delete all this crap right here and I'm going to clean out all my classes so I just have a blank monster class a blank a ninja class and a blank enemy class now I'm going to teach you guys how to do what I was just talking how to call the attack function on every single enemy object and have it work beautifully now before you're saying oMG you deleted everything I just follow the tutorial and now I'm going to have to retype all that code why would you delete everything well I deleted everything because the code for this is actually a whole lot easier than what would be doing before so before I wanted to stress you guys you know how you inherit and indeed you can you know use different addresses with different pointers and once you understood the last tutorial come to this tutorial and look how easy I'm going to make this for you guys so we want every enemy object to be able to attack so let's go ahead and make a public function and we're going to name this void attack so now every enemy has the ability to attack so now what we want to do is before we start coding the rest of the stuff we already know that whenever we build a specific class like ninja and monster that they're going to have their own specific attack functions an engine is going to be like karate chop and a monster is going to like roar I'm coming out from under your bed well we already know that each of these classes that is going to pretty much overwrite this attack function so what we want to do is we want to make this function virtual whenever you make a function virtual it means that you're going to be using it polymorphically and that way whenever later on we're using like enemy 1 attack enemy to attack it knows that it's supposed to look in the specific class for that function instead of using this funk right here so now when we go ahead and you know public make our attack function using void attack and we'll just whoa easy back slashes now whenever we write something like void and just right you know ninja attack and line and let me just go ahead and code this real quick copy this paste it right there and the monster attack can be like monster attack so now whenever we go ahead and use well I might as well just code the rest of this program because you know instead of telling you what I'm going to code is we're just shut up and code it so we have a ninja object and we have a monster object now we know from the last tutorial that what we can do is sense a ninja is just a specific type of enemy we can go ahead and make an enemy object like enemy object and make a pointer to enemy one get my cursor out of the way and we can set this equal to the address of ninja whom can do the same thing with monster and this is valid again because monsters and ninjas are just more specific types of enemies so anything that you can do to an enemy including attack you can do to a ninja and a monster if an enemy can move around a ninja in a monster can move around if an enemy could stab you with sword a ninja in a monster could stab you with a sword so that's why we were able to do this right here so now what we can do is since we made this virtual function we can now go ahead and do stuff like this enemy one attack and let's just go ahead and copy this right here and now we can go ahead and write enemy to attack and if you run this it works perfectly fine ninja attack and monster attack so basically whenever we use virtual functions were telling C++ this our a so C++ let's sit down and have a conversation we're going to be building a computer game and we're going to be putting enemies in it now each of these enemies is going to have its own specific attack function now whenever I call an enemy object I'm going to have an attack I don't want you to use this attack function right here this is just a template telling you that each class that inherits from enemy is going to have a tech function whenever I use an enemy object that has an attack function I want you to find out which address aka which type of enemy has that attack function and call that attack so basically it said our right enemy 1 attack ok let's go ahead and I'm going to call attack from enemy hold on enemy 1 is indeed a ninja object so I'm going to ninja attack and then set re and me to attack well I know that enemy 2 is an enemy object so I'm going to go ahead and call it tak but hold on this is a virtual function so I'm going to go ahead and see oh that is a monster object so I'm going to go ahead and monster attack you so virtual functions are basically template functions and any class that inherits virtual members whether it's variable or function or anything ritual is a polymorphic class because well not because that is the idea behind polymorphism that you can call this same function I mean check it out we're using an enemy object and we're calling this Sam attack function but it has different results so that is the beauty behind polymorphism that you can use the same function and produce different results so hopefully I didn't confuse you guys too much I think this story is a lot more clear than the other one that's you know what basically what polymorphism is that well first of all in order to have polymorphism you need this virtual stuff right here and also the idea behind polymorphism is that you can have different functions from the same type and I and I'm doing those little quotation signs with my fingers you can have the same function with the same type of object but you produce different results based on what address it's pointing to so you know that's it I don't want to confuse the eyes anymore anything I have left to talk about I'll talk about next story so hopefully you guys understand this a little better than last tutorial if you don't don't worry we're going to be covering it more in the future but uh thank you guys for watching don't forget to subscribe and I guess I'll see you guys in the next video alright guys welcome to your 57 C++ tutorial and in this story I'm going to be going over a couple things I'm not going to be doing a whole lot of coding so you guys just might want to put away your keyboard for this tutorial and just you know sit back and watch and learn I'm going to be talking about something called a pure virtual function and also abstract classes and actually they both go hand in hand so you know you aren't really learning you know two totally new concepts but let me go ahead and before I talk about a pure virtual function let me explain you guys what a regular virtual function knows so let's go ahead and before we even start let's notice that this enemy class has an attack and this ninja class has an attack and this monster class has an attack so let's go ahead and actually code something in this enemy class attack and let's code something like C out I am the enemy class now I don't know that's good enough and let's go ahead and end that line so let's go ahead and run this program and see what happens it says ninja attack and monster attack it works as we expected so basically what a virtual function does is this whenever we're programming in using polymorphism for example if we made it if we made an object from the enemy class it would go up let me explain this one more time if we made an object from the enemy class and tried to use that attack function right here what did it do is it would go up to the enemy class and call this attack function but since this attack function is virtual it would go back down and say alright it was a virtual function which means I need to check what I'm pointing to and if one of these derived class overrides this attack function then use that one instead so that's why even though we inherited this attack function that says I am the enemy class we overrode it in these derived class one bump says ninja Tech and one of them says monster attack so since we overrode it right here and since we're using polymorphism with virtual functions that virtual function checked inside that we were indeed overwriting it and used those more specific functions so now let me talk to you guys about what a your virtual function is so let me go ahead and maybe this will be easier if I saw if I go ahead and take out this attack actually let me just go ahead and cut this from the monster class well this monster class is already inheriting an attack function from the enemy class if it doesn't implement its own specific attack function it inherits the default general I am the enemy class so let's go ahead and run this and it says ninja attack had its own specific attack function but the monster attack did not so that's why I inherited the more general enemy class one simple enough so basically whenever you have a virtual function you have the option of overriding it but if you don't it's no big deal because we already have a function right here that we inherited but with a pure virtual function in before I start talking about that let me go ahead and paste this code right back in here a pure virtual function doesn't give you the option of inheriting from the base class in order to make a pure virtual function you don't have a body at all in instead of a body right here what you have is equals zero so basically you're saying this virtual function which we see equals zero instead of a body is now a pure virtual function and as you can see a pure virtual function has no implementation whatsoever and by implementation I mean body my body it means I mean it doesn't do anything so a pure virtual function doesn't do anything at all in one rule that you have any derived class that inherits from this from a class that has a pure virtual function in it it must must it needs to no exceptions it needs to overrate that function so remember last I mean yeah the last example I told you we had the option of taking this out and if we took it out it was no big deal we'll just use this stack function well now in every run it says uh-uh you get an error message right here and the reason is because this you made a pure virtual function in C++ in the programmer made a deal he said alright programmer whenever you make a pure virtual function you need to override it that's our deal so in this class alright you did a good job but in this class you didn't overwrite it at all so whenever I try to call this attack function right here nothing's happening equals zero so that's why whenever we use pure virtual functions we need to overwrite it so that can be good and bad depending on what you're going to try to program if you want to make a game or something that you know if you don't want a monster to have a specific attack it can just inherit the enemy attack that's fine then you don't want to use this but if you want to make a game with a bunch of different monsters or something and you want each of those monsters to have a specific way of attacking then you would want to use a pure virtual function because whenever you use a pure virtual function it's going to make sure that you overrode it so now that we overrode in both the ninja class and monster class we're going to go ahead and run this and it's going to work just fine and you're saying all right so I understand what a pure virtual function is but what is an abstract class well this is like the easiest thing you ever learned an abstract class is just a class with a pure virtual function in it pretty easy huh so it took me like five minutes to describe what pure virtual function was and then you know like five seconds to describe what an abstract class was so let's go ahead and recap one last clock one last climb one last claim no one last time all right abstract classes are just classes with pure virtual functions in them now whenever you make a pure virtual function you don't have a body you don't have curly braces you don't have any implementation whatsoever it's just a function that says any derived class needs to overwrite this function it's just kind of checking to make sure you overwrite this function now regular virtual functions have the option of being overridden in the drive class so if this was just a regular virtual function then we can go ahead and take this attack out if we already can go ahead and include it but a pure virtual function we need to overrate this attack function and give it you know some code to run we just can't you know run this equals zero or it's a computer is going to flip out so basically before you could make an enemy object that use attack wait let me think how I'm going to say this well basically I just said all I needed to say I'm just going to you know tell you guys how it works in my program but I think I just said everything I need to say so basically well you know I'm not even going to do that because I did explained it like five times so anyways that is what pure virtual function is in all abstract classes is a class that has a pure virtual function in it so I don't know if in the next lesson I'm going to be showing you guys how to make a you know how to put polymorphism to use or we're going to be moving on to another subject but either way it's going to be amazing so stick with me and uh yeah we're almost done with polymorphism either way so if you know stressing you out just take a deep breath and you know the end is near so thank you guys for watching don't forget subscribe and I'll see you guys later alright guys welcome back to your 58 C++ tutorial and in this tutorial I'm going to be talking to you guys about something called a function template now before I actually you know just give you guys a definition and show you guys an example let me go ahead and throw a quick scenario at you guys so say you're working for Microsoft and your boss Bill Gates comes up to you and he's like Bucky I need you to create the world's perfect calculator so say alright bill let me be I will do this so the first thing you probably do is this you're going to create a function maybe to add two numbers together add two integers together so you're going to write in is your return type name the function add crap because you know it's the most professional thing I could think of and then you'd write like int a and int B for your two numbers and then all you need to do in the body is you know add them together and return them so like return return a plus B so there's your function right there add crap it adds two numbers together so whenever you want to use it in your main you need you know two integer variables like int X equal 7 y equals 43 and we'll sort the answer and variable called Z so now we would put Z equal to what I named it add crap and we would just throw our two variables in here by the way I got a new keyboard the other day and it's really different so I keep like hitting you know the wrong keys that are only one off so you know just deal with me if I have a lot of typos in this story so anyways what we do is go ahead and throw our two variables in there and then you know just print it out and screen make sure I didn't mess anything up so see out a Z and lime so let's go ahead and build and run this and make sure we didn't get any errors and we get 50 and upon checking we find out that forty-three plus seven is indeed 50 so that is our function add two integers together but he didn't say I want program to add two integers together he wants a calculator so we're saying our a so we have a bunch of different you know types of numbers besides integers we have a flow along double um you know every you know sum with decimal points I'm just with basic integers so we're going to need to take this function and you know copy it and you know basically make the same exact function but make this one using doubles make this one using floats make this one using long and as you can see already this program is going to get huge and it's going to get messy and if we ever decided that we messed up something like we put minus here and set a plus we're going to need to go back on every single function and fix them all and it's just going to be a big pain in the butt sir saying all right since this function pretty much is doing the exact same thing wouldn't it be nifty if we could just instead of this in trite here just replace it with like a generic datatype and throw in any information we want well that would be a little bit too easy or what it is there a way that we can indeed build functions that could handle multiple types of data well you guys are in luck because that's exactly what I'm going to be teaching you in this tutorial instead of building a function that can only handle one type of data if you know we're building a bunch of different functions that did the exact same thing why not code this to handle multiple types of data well in order to do that we first need to build something called a template definition and what a template definition is going to do is we're going to be building a generic type of data basically all we're going to be doing in this line of code so let's go ahead and in order to do that you first write the name template and now inside angle brackets right after it you write class then you give your class a name like Bucky now Bucky is pretty much a template it's not you know an integer it's not a flow it's not a character it's just a generic type of data so then we can use that generic type of data let's go ahead and copy Bucky and instead of you know having int or double or long we can just go ahead and type in our generic type of data anywhere we would use you know a specific type of data so now your return value is Bucky instead of passing it in an integer called a you're passing it in a Bucky called a and instead of passing it in an integer or float or double called B we're just passing it in a Bucky called B whatever the heck of Bucky is so now let me go ahead and run this and I'll show you guys that this works beautiful beautifully just like that so what's happening is this instead of building functions that take you know that take two integers and return an integer we can just throw in generic data types instead using this template definition right here so your template definition is pretty much building a generic type of data and then instead of you know taking a function that you know works with one type of data you can just use that generic type of data to work with any different type of data so you know we use the integer right here but say we wanted to use double and remember a double is just something with a decimal point like seven point six five or forty 3.54 and now whenever you go ahead and yeah I just accidentally press something let's go ahead and yeah now my computer is freezing that is yep and that's just great not responding that out now just go ahead I'm not in the middle of its oral or anything I can wait for you guys not minimize you you can stay there if you want let's go ahead and build and run this oMG are you flipping kidding me must be stopped to do a rebuild yes I want to stop it see that's what you guys get when you buy a new keyboard and all the keys are like all over the place I saw her this is like a keyboard oh wait a minute oh it was upside down okay it's fine now okay so as you can see instead of integer if we throw a double in here it causes the exact same function and it works fine so basically whenever women we make function templates we're doing this we're making first a generic type of data and instead of making a function specific to one type of data we're going to use that generic type of data and now whenever we call that function C++ is are going to automatically see that X is a double and Y is a double so you must be working with doubles here so instead of Buckey it's going to substitute the word double that's literally what it does it puts double right there and double right there and double right there and it runs it just like that and now if we go ahead and we had an integer like seven and 43 it will take anywhere where it said Bucky and it will change it into int int int int so as long as we have that generic type of data like that it's going to go ahead and it's going to work with any data we have the one thing that you can't do is you can't have an integer X and a double y you can't have two different types of data um well actually talking about that there is a way that you can make a template functions that take different types of data but for now I just want to cover whenever you have a function that does the exact same thing and you want it to be able to work with multiple types of data you can build a template function and what that means is you're pretty much building a generic type of data and you're going to be using that generic type of data inside your function instead of you know integer years or doubles or anything like that so then whenever you use your function later on you can use it with integers doubles or you can even build it to work with like strings and characters if you want but you know you can't really do that using addition so so anyways in this tutorial we learn how to work with one type of data using a function template in the next story I'm going to show you guys how to work with multiple types of data like how to add an integer and along together or a double and a float and all that good stuff so thank you guys for watching and I'm gonna go take a keyboarding class for this keyboard and awfully when you come back I'll be a little bit better so one thing you guys for watching and I don't forget to subscribe and I'll see you next video what's going on guys it's Bucky and welcome to your 59th C++ tutorial and in this tutorial I'm going to be teaching you guys how to use function templates but instead of just a single parameter like last time we're going to be using a multiple parameter so let me go ahead and explain you guys what the heck I'm talking about first you know in the last story I taught you guys how to build basically a generic function to add like two integers together or to add two doubles together well in this tutorial we're going to be able to work with two different data types for example we're going to be able to take an integer and double and add those together or maybe you know a long and an integer and add those together so they don't have to be the same data type all the parameters we pass in we can work with two different types of data in the same function so we're going to set this up a little bit different then we have before so let's go ahead and first get two different types of data to work with so let's go ahead and make an integer variable X and set this equal to 89 or any integer you want and go ahead and make another you know double variable it really doesn't matter the data type as long as they're different so pass it in a double Y and set this equal to you know some fifty six point seven eight or something like that so now what we're going to be doing is we're going to be building a function to compare these two numbers and just return whatever number is smaller so in this case it would return fifty six point seven eight so let's go ahead and pass in those two numbers X and Y and hopefully if we build our function correctly it will print out the smaller number right on the screen so let's go ahead and set up this function template right now so like before whenever we're building a function template we always need the keyword template but we need to spell it correctly template just like that and now unlike before where we just had one generic class and we named it Buckey or something we're going to be working with more than one generic class so make sure you name your classes something that you know you can work with later on I like to just name mine first and second and by the way I might as well mention this to you guys you guys are going to see this a lot like cap t in capital u it's like kind of a programming standard to use one capital letter whenever you're making a template class but I really don't like doing that I like you know something a little more descriptive like first and class second um you know if you're in like a programming class or you're watching this because you forgot how to do this for your job or something you typically want to use one capital letter but whenever I'm programming you're just gonna have to deal with it so now that we have a template this line is pretty much saying this we're going to be working with two data types but we don't know what those data types are yet so we're going to be giving them generic names so first and second so whenever we're building our function you first write the return type which is first and now our function name was smaller and it took two parameters one number and we'll call this one a and another number and recall this one B in all our function itself does is hello and all our function does is it takes two numbers and returns whatever one's smaller and we can do that by writing one nifty line of code if a is less than B then return a if not return B so it's going to be saying all right is a less than B if it is return a if it's not return B so it's basically going to return to you the smaller number so now let's go ahead and now that our function is working properly let's go ahead and test this and make sure it works as you can see we compared eighty nine and fifty six point seven eight and it turned that double 56.7 a into an integer and you're saying all right we just compared two numbers so shouldn't be giving us um just 56 point seven eight why did it chop off to seven eight that's because of this whenever we built our function template it pretty much saw what type of data we were passing in so we're saying alright we want to get the smaller of two numbers we want to first pass you in an integer 89 and then a double 56 point seven eight so I said all right make first in anywhere you see first change it to an integer so it said re I'm going to change this to int this to double I'm going to return an int because that was the first thing we passed then so since this return type was the first type of data we passed in it converted this double to an integer because remember anytime you saw first it converted it to an int we could have change this around we could have you know passed this one in first so it was Y X and whenever we did that we would get 56 point seven eight in that way we could have more precise because in this case scenario the first thing we'd pass then is a double and the second number we pass then was an int so whenever it's looking at your template wherever it sees first it's going to replace it with double and that includes the return type right here in the first parameter and the second parameter would of course be an integer so it will take a double and an integer and since it returned a double that's why we got back the double so basically what I'm saying is this whenever we're working with two different types of data you need more than one generic classes or pretty much placeholders basically a generic or excuse me basically um a generic class is just a variable for the type of data instead of the value itself does that make sense to you guys so instead of having a variable for this you have a variable for this simple enough and these variables can only be types of data like int double long yada yada yada so basically people usually build these templates to work with um you usually don't see more than three or four it's usually one or two but yeah that's basically how it works anytime you want to build a function template that takes more than one type of data you need to separate them into more than one generic classes and then you can use those generic classes just like you would any other type of data so hopefully you guys understand what that means arm again if this is just too confusing and you don't want to keep track you can go ahead and build a lot of overloaded functions and it's going to work you know just fine but if you want to use this it's going to save you a little bit of coding and you know it's a little more confusing to look at but once you got it down you know it makes your life a whole lot easier so thank you guys for watching I don't forget to subscribe if you have any questions just ask me on my forum and I'll try to answer them for you guys sometimes I'm busy but I can usually answer them for you guys so thank you guys for watching and we can subscribe and I'll see you guys in the next video alright guys welcome back to your 60th C++ tutorial and in this tutorial I want to talk to you guys about class templates so before we learned about function templates but in this tutorial I want to tell you guys aside from just functions being able to use templates entire classes can use templates as well and again by template all I mean is a generic data type so let's go ahead and build it right now so just like before the way you make a template definition doesn't change you go ahead and write template and then inside your angle brackets you write class and I might as well you know start good programming practice and use what people typically use and that's just one capital letter instead of you know a word you can use a word I like using word but since I'm teaching you guys might as well get into a good habit so now after this now we basically made a generic data type we can begin making our class so go ahead and name a class I'm going to name mine Bucky and let's say that well let me add my semicolon before I got before I forget Bucky is going to have two variables now we don't know what those variables are yet whether they're in stubble so I'm just going to name them T my generic data type one is going to be name first and one's going to be name second so now let's throw a couple functions inside Bucky so they're both going to be public might as well go ahead and make our constructor Bucky and in our constructor let's just go ahead and for two numbers set first and second equal to whatever numbers we pass in so T a and T B basically we're passing in two numbers which we don't know what type of numbers they are yet so now let's go ahead and set first equal to a and second equal to B so now these two numbers and Bucky are going to have a value so that's what's going to happen whenever we first build a Bucky object so now after this we can go ahead and you know just add another method like t bigger and all this is going to do is it's going to find out which number is bigger will actually keep this constructor definition right in here well we'll take this bigger function and we'll build outside because there's a couple different rules I want that you guys whenever you build a function template what I say function template what the heck is that whenever you build a function member outside the Declaration of class template so let's go ahead and do that right now and make sure I have all my semicolons in the right place I looks good that's good one down there looks good so far I guess we'll find out later on when I run it but okay now the first thing I want to know is that even though we made a generic type of data right here whenever you have a function member outside the Declaration of the class and remember we said we're going to be building a function called bigger that belonged to the class Bucky but we're going to be doing it outside the class we always need to have that function definition again so go ahead and copy this and paste it I don't know why they made it where you need it again but they did so before every single function you need to have that now here is how you start out building your function members outside the Declaration of the class template you first write your return type and our return type is of course T just our generic return type and then just like before you write what class you're going to be working with so I'm going to be working with Bucky and I'm going to be building a function called bigger but we just can't go ahead and type you know the function body right here we need to do something first right after your class name you need to add angle brackets and add your T right here too and this is because we need to tell C++ at the functions template parameter is the same one that we're going to be using for the class so in order to do that we need to specify that T inside angle brackets right after we class name everything that's kind of weird well I agree with it it is kind of weird and it's kind of stupid too but if you think this is stupid and complicated you're going to have to take it up with the people who made C++ I just teach it for the record I don't think it should be made this way but you know after the class name you need to include that function template parameter again I think it's a stupid way of doing it but hey I didn't make C++ I just teach it so now we can go ahead and you know what well of course this function called bigger is just going to take the two numbers that are in the Bucky class first and second and it's going to find which one is bigger so it's basically going to be the opposite of what we did last time so just go ahead and return and we'll compare if first is bigger than second then return first else return second so this looks good go right now now well I think that's all we have to do for a class so basically we have a class called Bucky now Bucky has two variables in it a first and a second variable now whenever we make a Bucky object that's when we give the first and second variable their values so first is going to be like 10 and second is going to be like 20 and now we have another function just to find out which number is bigger so whenever we call the bigger function it's going to take the first number and the second number which would be like 10 and 20 if 10 is bigger it's going to return 10 if 20 is bigger it's going to return 20 so now let's go ahead and make our Bucky object and run this and let me show you guys how it works so if you think you guys know how to do this you don't because there's one other little weird thing that you have to do you go ahead and make your Bucky object that just as you think you would making Bucky Bucky object and since this is a constructor that takes two parameters first and second we need to give it its two numbers like 69 and 105 and now after this we can go ahead and you know see out bo the bigger and remember this bigger doesn't take those two numbers as parameters since this class already has two variables in it it's just going to go ahead and grab those variables so as you can see in this bigger function we don't need to pass it in those two numbers it already has it so let's go ahead and build an around this and say all right what the heck is this why are we getting an error message that's because whenever well let's read the error message I'll show you guys what it says missing template arguments before Bo whenever we're working with the class template we need to explicitly tell it what type of data we want to substitute for T and we're going to be working with integers because 69 and 105 are integers so between your class name and your object you need to pass in I and T in angle brackets so like I said before before we go ahead and start making these objects if you think you know where you're doing you don't this is what people typically forget so in the last couple tutorials we could have done this it was optional I decided to exclude it well in this tutorial we absolutely need to have it and whenever we do this we're basically saying all right this is what we're going to be substituting for T so if this was double and we made our class object anywhere this class saw T it would plug in double right here these two numbers are doubles when our constructor is made we're going to passing in two doubles whenever you run the function it's going to be a double instead of a T well since we're going to be working with integers we're basically telling our class anywhere you see a T substitute integer for it so that way we can work with you know different types of objects and you know maybe we'll make one class an integer and one plus a double and well let me go ahead and first run this and show you guys that it indeed works 105 is indeed the bigger number and if you don't believe me I'll just change this you know 258 and run it again and show you guys that our program is working correctly so basically there are a couple weird rules the first rule I want to tell you guys is every single function you build you need to precede it with this function template it's kind of weird but it's what you need to do also you need to have the blank generic data type after your class name and this pretty much tells your function that we are indeed working with the classes template parameter which is this one and also the last thing you guys got to watch out for is whenever you make your objects you need to explicitly tell your object what type of data to substitute for T and you do that between your class and your object declaration right here so there are a couple of weird rules again I want to say this if you guys are stuck on templates and this is just way too confusing for you guys all the substitution forget about them you don't need to build it it's just if you want to build a program that takes less code and makes it a little bit easier then you have the option doing this but it isn't a requirement so if you don't completely understand it don't worry about it you can move on and you know you're not going to be lost in C++ so anyways thank you guys for watching don't forget to subscribe don't forget check out my website and I will see you later what's going on guys welcome to your 61st tutorial and in this sorrow I'm going to be talking about something called template specialization specialization there we go might take me a few times to get it but basically what template specialization is is it's a way to make a class that has a different implementation when a specific type is passed into it for example if we made a regular old template like before we could pass any data type into it like integers doubles characters and it's going to be able to handle any of that data well in this tutorial I'm going to be showing you guys say for example you want to build a template to handle all numbers but you want it to do something a little different when it handled characters because you know let's say you wanted to build a class that handle numbers and added them together well you can't use all these same functions whenever you're adding letters together or else you're going to get a bunch of error so it's basically a way of working with a specific type of data in a different way than you would regular so let's go ahead and the first thing I'm going to do is build a regular template and I'm going to compare it to this new specialized template so our boss came up to us and he's like Bucky why is he talking to us and only using my name I'm not sure but he's a little weird so he's like Bucky I wanted to build a template to handle all types of data however if the user passes in a character which is this one specific type of data I want you to work with it in a different kind of way so one class or one template is going to take integers doubles floats any type of data we pass in to it but whenever we pass it in the character it's going to hand it a little bit differently so after me talking for two minutes it's finally time to start coding so let's go ahead and build a regular template and this is named class T so remember T can be any type of data and I'll just call this class spunky because you know kind of in the spunky kind of mood did anyone ever used to watch Rocko's Modern Life what was that dogs am I'm pretty sure it was spunky but let's go ahead and make a public and the only thing I'm going to be making in these classes is just a simple constructor because I don't need to demonstrate a whole lot I just need to demonstrate the concept and you know not build a huge functional class so in order to make a constructor you of course write the class name which is spunky and pass in any type of data and we'll name a variable X whenever we first create an object so all we're going to do is we're going to create a class pass it an object and print it out on the screen so see out X and then go ahead and write something like is not a character because we're going to be passing in any type of data like a number and it's going to make five is not in a character or 6.17 is not a character so this class is going to handle everything besides characters basically so let me go ahead and make sure I got all my semicolons in the right place and let's go ahead and see a quick example right now so actually I'll wait to show you guys an example not yet I'll make you guys wait so this is how we build a basic template it can type take any type of data we wanted to integers characters floats doubles and it could say whatever thing we passed in like J is not character for is not a character eight point seven six is not a character and it's going to work fine with any type of data that's the beauty of templates so say whenever the user passes in a character we want it to be able to do something differently well that's where template specialization comes in and in order to do this go ahead and type template with empty parameters right there or empty angle brackets this is the line where we tell C++ we're going to be using template specialization and in the next line we're going to tell it what type of data this class should handle so this again we can name it the same class as before because the main implementation doesn't really change it's only the data type in concept and the class or excuse me and you write your class name and in between the ankle brackets after your name you write what type of data should this class handle all right this is a special class that I want to handle characters characters only nothing to do with numbers or any other data type anything like that this class is only going to be four characters so again one last time the only thing that's really going to change is this line which tells C++ we're going to be using template specialization and this lat class that says all right since you're using template special it specialization what type of data should that specialize in and this class is going to specialize in characters so let's go ahead and make that constructor public and of course it's the same spunky however in your parameters after you don't write T X because remember T is a generic data type since this class is only four characters go ahead and write character right there and now the body is just like before let's go ahead and copy this copy right there and paste it right there except um we can't have X is not a character we can write X is indeed oops no more explanation points indeed is indeed a character so basically how our program is going to work is this we're going to be creating objects and we're going to be creating objects of a bunch of different types integers doubles characters whenever our computer program comes across the character it's going to handle it with this specialized template any other type of data besides character it's going to go to this generic template or generic class so you know any numeric data such as integers doubles floats yadda yadda yadda this is going to handle it but once it sees it's working with the character it's going to handle this class right here so it's going to be like 4 is not a character 8.0 is not a character but if we throw in something like J or Z it's going to say Z is indeed a character so don't believe me well let me go ahead and prove it to you guys so the first thing I want to mention is I know I didn't tell you guys this but you can explicitly well let me say this whenever we like past in a data type before C++ already automatically recognized what type of data type that was but you can also do something like this um you could throw in your angle brackets data type right after the class name and this helps C++ out and oh great there's a motorcycle driving buddy right now and this helps C++ out by it basically changes this to T or it substitutes T for the data type it's kind of just uh you know a nice little hint for Objective C so let's go ahead and make object one and since we're going to be working with integers we'll go ahead and we pass in seven so now let's go ahead and copy this save us some typing and now let's go create two more objects so two and three and our next object work a double and remember a double is basically something that you can use decimal points like three point one five four and now for our third one let's go ahead and use that character and remember a character is just a letter so arm Q or something like that so basically what's going to happen is this it's going to come across this ceases working with integers and use this generic template right here when it gets the here is going to be working with doubles and it's going to use this generic template right here when it comes across this is going to be working with characters and it's going to say hold on a second you have a special class right here just made for working with characters so on this one I'm going to print queue is indeed a character so let's go ahead and build to run this if I forgotten I semicolons and it looks good so seven is not a character seven our excuse me three point one five four is not a character Q is indeed a character so as you can see these first two lines right here usually use the generic template class and the last one whenever we had a character in there it used that specialized character template class so there you can see the beauty of specialized excuse me they're called template specialization so there you go it's basically a specialization with one data type in other word you have a different implementation when a specific data type is passed in in this case character so there you go I hope you understand it if you don't just go ahead and ask me on my forum or leave a comment below and I'll try to answer it for you guys so thank you guys for watching don't forget subscribe to my channel and I'll see you guys in the next video what is going on guys welcome to your 60 second tutorial and in this tutorial I'm going to begin talking about something called exception handling now an exception is a way of handling an error that might occur when your program is running for example if you built a calculator and the user is trying to divide by 0 that may be a error that occurs when the program is running or if you know you have you made a game and you need a user to register if they try to use like 999 as their age that's unacceptable so that may cause an error to occur so let's go ahead and take a look at the syntax for this now the first thing we need is something called a try block now in this try block this is where we write the code that we want to try aka the code that we think error might occur so let's go ahead and make something like I'm going to be making a simple program that takes two ages the mother's age and the son's age now we all know that a son cannot be older than its mom so whenever the sons age is greater than the mom's age this would of course cause an error so let's go ahead and make two variable int mom's H and int sons actually might as well summon equal to values right now and mom's age equals like 30 and its sons age we'll set this equal to 34 now we all know this is impossible so let's go ahead and test it right now so if the son's age is greater than the mom's age then we want to go ahead and we want to do something called throwing an exception now it's basically this whenever you have something that occurs that shouldn't occur we need to tell the computer that an error did occur and we do this by throwing an exception and in order to throw an exception exception go ahead and type throw and then type an error number and you can make this any number you want you can actually do other things besides numbers but just throw a number because later on say we made a program that check for you know 20 different types of errors we want to know what air ha so let's go ahead and we already know that in our little manual 99 means that the mom is younger than the Sun so you know it's pretty much just a reference number so anytime we get an exception and remember anytime this line of code is going to run it basically means that an error occurred so now that we know an error occurred we need a way to handle that error because we just don't want our program to freak out and shut down so in order to handle the air we do something called catch the air catching the air allows you to pass in that number which is 99 so now X is equal to 99 and we can handle it a certain way for example we can just output to the user on something like this son can not be older than mom um and then for reference or a err number and this is where we write that's X right there in line and just scroll head so you guys can see what I'm typing so now if you go ahead and run this we can see all right whenever this program runs and the kid is older than the mom then we have error message that pops up that says son cannot be older than mom err number 99 so you know this is pretty much just for our reference this error number but let's go ahead and say that the mom was indeed older than a son the mom was like 50 and the son was 34 well this is going to work fine and this is never going to happen so no error is going to be thrown no exceptions are going to be thrown so this catch block is just going to be skipped so let's go ahead and run this and we don't get any error messages this program works perfectly so basically the concept of this is or oh is this an exception is a way of handling errors that may occur when your program is running for example if the user tries the divide by zero or pretty much if the user does something they aren't supposed to do now in the try block right here this is where you write the code where the air might occur and right after it you need a catch block now the catch block is basically what what to do if there is indeed in air and if there is no air in this try block then the catch block is skipped all together and just like a function a catch block takes parameters so it can take an integer in this case such as 99 and that's pretty much just like an error number you know whenever you're just playing on your computer and windows messes up you know how like the error message pops up well that's pretty much what we're doing right here it's like error message to the yada yada yada do you want to send to Microsoft or do you don't want to send by the way does anyone ever send those do they really get those error messages I don't think so but anyways now you guys know the basics of exception handling and by the way if you guys are saying you know what Bucky I could just have used an if statement and you know made a separate function for this well I know that we can do this a different way but um exception handling is useful whenever you're trying to you know do computer stuff like allocate memory I just want to show you guys a real easy example for this case but I know that you could have probably made this program just by using a basic if statement and you know maybe a simple function or something but I wanted to demonstrate the try and catch block in how to handle an error message so these are useful for a lot more than you know comparing two variables and there are some instances where we can't just make a simple program that we need to use this exception handling so for now I just want to tell you guys that so I guess in the next tutorial I'm probably going to show you guys another example and show you guys how you can use a different parameter for this catch block right here but for now that's all you guys get so thank you guys for watching don't forget subscribe and I'll see you guys in the next tutorial what's up guys welcome to your 63rd C++ tutorial and in this story I'm going to be showing you guys another example of exception handling so let me go ahead and I want to cover you know one other little inky dinky thing it isn't a main concept but if I don't cover this I'm going to you know it's like OCD I need to cover or else it's going to bug me for the rest of my life so let me go ahead and first what I like to do is this whenever I'm working with exception handling I like to set up the framework first so I like to go ahead and put try right there and after this put catch with my parameters right like that and that way whenever we get you know type in a bunch of code in here I don't have to go search and be like alright what's this curly brace go to with these parentheses go to it's really easy if you set up the outside first and work your way in then that way you don't get confused so let's go ahead and in this program I just want to build a really simple calculator I'm going to have the user input two numbers and I'm going to make sure that the bottom number is not zero because remember you're not allowed to divide by zero or else the you know your computer is going to blow up so what I like to do first is a well before I even do that let's go ahead and just start with the program so let's go ahead and make two variables in num1 and i'll save in um two for later so let's go ahead and give the user prompt like see outs and we'll just say something like enter first number and line and now let's go ahead and give them a way to enter that number into number one and by the way I read this a couple days ago and maybe this will help you guys understand this arrow on this arrow the arrow shows the direction that information is flowing now whenever you output something it goes to your computer screen so this text is going to your computer screen now whenever you input something it gets inputted and stored as a variable on your computer so the text that you enter is going to be stored in a variable in your computer you see where the informations phone to your computer screen to your computer basically the information is flowing to the user and back into the computer pretty cool huh so I probably should have said that in Lycia my second tutorial but you know 63 tutorials in I guess is better late than never so now the user entered a number and it's stored in the variable number one so now let's well I might as well just copy this right here and copy this and paste it right over here and we'll change this to two so enter two it's going to be sorted two and enter second number pretty good so now after this what we want to do is it really doesn't matter what number they answer for you know number one as long as it's a number but number two it does matter because the second number cannot be equal to zero because if we remember from you know fifth grade math class or whatever you can't divide by zero it's illegal the math gods will not allow it so let's go ahead and have an error message pop up whenever you try to divide by zero and we can just go ahead and put a simple if statement if num 2 is equal to zero let's go ahead and throw an exception so we'll just throw the number zero and now what we want to do is remember if number two is not equal to zero that means that the numbers that they entered were valid so we'll just go ahead and print out the answer on the screen num 1 divided by num and in that line so basically if they enter zero is the second number we're going to get a error if they enter two valid numbers is just going to print out the answer by dividing the top number by the bottom number so if we do indeed get a error remember in the last tutorial I tell you guys that you can pass in a number two uses like an error reference number and you can just erase something see out you can't divide by X and that way whenever we throw zero it's going to pass zero and as X and it's going to say you can't divide by zero so let's go ahead and run this and see what happens enter the first I'm going to first run a program that works perfectly and our 32 buffer my first one enter 16 for my second one and 32 divided by 16 is indeed 2 as you can see here so my program is working beautifully but let's go sit ahead and say that we have an idiot that's gonna you know never knows how to use calculator and is going to try to divide by 0 okay 32 okay everything is going good so far but then I'm going to try and enter 0 is my second number and whenever I try to hit this and solve this riddle we can see you can't divide by 0 so as you notice as soon as you get a error message it basically just jumps right down to this catch block right here and it says hold on you did something wrong here's your error message you can't divide by 0 so now the little itty-bitty thing I want to cover in this story is this you can have multiple catch blocks to catch different types of error messages right now the only type of error message I showed you guys is the integer error where you can catch a double arm you can actually catch a character if you want you catch any different type you want now aside from covering that I don't need to show you guys you know the different types of error messages you can catch but what I do need to show you guys is this little thing right here dot dot dot you're saying what the heck type is this a dot dot ok I understand that I can catch you know intz and characters whenever you just want any error message to be caught for example you don't know what error message is going to happen in this try block at any time any error message occurs you just want it to be caught right here then you can use the da-da-da-da-da is pretty much the all encompassing the default catch so basically if you have in so basically anytime an error message is thrown it's going to be caught by the dot dot no matter if it's sent in character yadda yadda yadda so with that being said this is the catch that you see most often I just wanted to throw you guys the piece of information that you can indeed catch specific types of error messages but this is the one you're going to see more often so let's go ahead and try and run this and it says alright and once again I did something wrong oh I see what I did I actually tried to pass an X and X is no longer existing so I'm going to go ahead and try to run this one more time and you see it says enter first number 32 and then we try to divide by 0 get error message and we get that default you can't divide by error message so typically you would want to write something like this it would probably make more sense but anyways I just want to stress you guys that aside from catching different types of error messages you can also catch general error messages and that's what we're going to be doing most of the time so now that you understand that you understand most of everything there is that know about exception handling there are a couple other things that uh I don't even know if I want to cover or not there's like passing in objects that you can catch and also um you know inheriting from exception classes and default messages and stuff but I really don't know if I want to get in that I mean we understand the basics so in the next tutorial don't know if I'm going to be covering more about exception handling or you know jumping into the next but either way it's going to be amazing so if you have any questions check out my form the new boston.com slash forum and yeah I guess I'll see you guys in the next video what's going on guys welcome to your 64th C++ tutorial and in this tutorial I'm going to be beginning to talk about files now we need to be able to work with files because files are what you use to save data on your computer you're saying hold on Bucky I know what's used to save data we can just you know store the data and variables or something like that well we can't exactly do that for permanent data for example whenever we store data and variable and we close out of the program or maybe we want to shut down our computer that data is going to get wiped out now in order to save data permanently what we need to do is we need to store it on file on our computer and what this does is whenever we're working with files it stores it to your hard drive it permanently edges it in there so then whenever we shut down our computer we can go ahead and pull it back up and everything is going to be working fine for example if you were playing a computer game or if you had to write an essay for school you wouldn't want to just store all that information and variable because then the user would have no way of saving that data so what we're going to be doing is we're going to be working with files storing them on the computer's hard drives and that gives our user a permanent solution to save data very useful and well you're probably going to be working with files in every single program you're using unless you know you're just making a cool animation or something so let's go ahead and the first thing I need to show you guys is we need to include an additional header file so let's go ahead and copy this save us a little bit of typing and instead of iostream we're going to put F stream right here now this is the header file that we need for file input and output without this header file we won't be able to work with files at all basically so that's your main file file I guess you could say so let's go ahead and now that we got everything included we need again this is to work with files this is the input and output data or basically how to add data to the file and read data from the file so there you go and let's go ahead and start coding now so here is how you work with files and c++ the very first thing you need to do is you need to build an object since c++ can't work directly with the file itself and needs to be able to go through objects just because you know whoever made c++ that's how they made it so the very first thing we do is we need to write o f stream right like that and this allows us well there are different types of file streams basically this is how you create a file object and right after this you give your file object a name any name you want I'm just going to name mine Bucky's file now we have a file object aka access to a file so now the first thing that we wanted to do after this is we need to associate this object with a file itself because if we're just working with this object it's like our a you have like a billion files on your computer how am I supposed to know what object this one or excuse me what file this object is supposed to you know represent well that's what we do in the next line of code and in order to do that we go ahead and type the name of our object and we open a file and we just do that using the open function without the star right there and without this right there we use the open function and inside is a string we pass in what file do we want to open now I'm going to go ahead and open tuna dot txt and you're saying all right Bucky I don't have a tuna txt file on my website orcses sorry I've been making a web tutorials way too often but ever seen all right Bucky I don't have a tuna txt file on my computer so is it going to crash whenever it tries to open it won't know whenever you're working with files in C++ and it opens a file that doesn't exist it's going to see that it doesn't exist and it's going to automatically create one for you for example my file is going to get created right here now as you can see in this directory there is no tuna txt file so whenever I try to open it it's going to look for a tuna txt file and it's going to say doesn't exist I'll create one for you so it's going to get created automatically and it's pretty cool because it saves a you know a line of code from how to create it so basically what we're going to be doing so far is creating a file object that way we have access to some file and in this line of code right here we're going to say what file do we want to be associated with this object well now tuna text file is associated with this Bucky's file object so now basically any input and output that we make to this object is going to be input and output in this file we just can't you know input and output directly to the file because C++ won't let us basically Bucky's file is the exact same thing it's tuna text file from now on so now we can go ahead and you know output characters that if I will read every one output for example you're saying all right how do you output to a file what are you talking about well just go ahead and instead of outputting things to your computer screen like we have before we use that operator right there those two little less than signs and we just write some text like oh I love tuna and tuna loves me and we won't in that line actually go ahead and put a new line just like that and now you're saying all right before I had C out right there and output it to my computer screen well now I'm going to go ahead and have Bucky's file right there and all this text is going to output to a text file instead of the computer screen so nothing is going to show up on the computer screen what this means this little operator is output this data to this location so before we were outputting the data to the computer screen and now we're just outputting it all to a file simple enough I mean the operator is pretty cool it works in that way so now like I said we basically associated a file with an object in these two lines and now anytime we use this object name it pretty much knows we're going to be it represents this file so it knows whenever we want output this text it's really outputting it to this tuna txt file right here so that's going to run perfectly but at the end of all your programs when you're done working the files you always want to close that object and what that does is any you know little memory or buffers or any resources that the computer is using when it was working with this file right here it's going to close them out and it's going to free your computer's memory so it's just good programming practice to do this so let's go ahead and type our file object buckey's file and just go ahead and type closed with no parameters so let's go ahead and run this program and as you can see nothing happens right here because we didn't output anything to the computer screen but if we go ahead and take a look at that directory we now have a tuna txt document that got created so if we go ahead and double click that the content of this is I love tuna and tuna loves me pretty cool huh so as you can see this would be useful whenever you're you know creating a computer game and you have a character with a bunch of statistics like health and you know happiness and hunger they can go ahead and play the game for you know an hour store all their data shut off their computer go to school go to work whatever come back and all their data is going to be right there for them it's not a new computer game every single time you start because that would be kind of waste time so that is how files are useful in computer programming and how to work with a simple text file so if you think you're done with files yet you got a long ways to go so in the next story we're going to be covering more about files and trust me there's a lot more information that we need to learn but for now thank you guys for watching don't forget to subscribe and I'll see you guys in the next video alright guys welcome to 65th C++ tutorial and in this lesson I'm just going to be giving you guys a couple tips when working with files and this is you know something that can save you time as well as some good programming practice so it's going to save you a lot of headaches in the future so let me go ahead and get started so in the last tutorial I told you guys that in order to work with files you first need to do two things you need to create a file object and then you need to associate that object with a file itself on the computer so let's go ahead and instead of doing that in two lines of code let me show you guys how to do it in one line of code so of course you need your of' stream because that's what object we're going to be making in order to work with files and then you give your object a name like buckey's file and then you might be thinking all right just go ahead put a semicolon go the next line of code put bucky's file you know open the file you want to work with but there's the easier way to associate this object with a file now whenever you create a file object it takes an optional parameter in the constructor actually the entire constructor is optional but if you want you can go ahead and do this all in one line of code by associating a file by passing into the constructor and then whenever you create your object it's going to associate that file with this object so for example let's go ahead and make a file name beef jerky text and now instead of creating your object on one line of code and then associating the file with this object on another line of code we can just go ahead and pass the file name into the constructor and now this file is associated with this object so it's probably better to get used to this syntax unless you're making a program where you don't know what file is going to be associated with this object whenever you're running it so usually I like to do it this way just because the save is a line of code and again this constructor is optional but trust me it's going to save you a whole bunch of time in the future so now you can do things like um Bucky's file and then just go ahead and output something stupid like I love the beef and it says oh I love the beef but you know good enough and then go ahead and might as well add a new line and then get my cursor out of the way and then of course it's good program practice to have Bucky's file close to free up any of our computer's resources so let's go ahead and actually watch this file get made so I'm going to go ahead and press run and oh man and close it out but anyways you can see now that we have a beef jerky txt file so let's go ahead and click that and it says ooh I love beef and i do love beef jerky can't lie about that so let's go ahead and before I let you guys go I want to tell you guys one more thing a function that you're going to be seeing a lot if you're working with the team of developers or you know if your teacher gave you a assignment working on the files is some function called is open now is open is a function that you can use on a file object and it's going to return true if the object is currently associated with a file and this is a way that you can check basically if a file is open and you know it's ready to be worked with so in order to do this go ahead and write if and then you do this write your file object which is in this case the buckey's file and then write your function right after it is underscore open now this isn't going to take any parameters and just go ahead and write something if the file is open then we'll just output on the screen like um okay the file is open good enough and then might as well go ahead and in that line and we'll say else if the file is not open then let's just go ahead and output like Bucky you messed up and will spell everything wrong and looks good go so go ahead and in that line so now what's going to happen is this all right we coded this line correctly and it did indeed open this beef jerky text file so whenever we check if the file is open this this is open really isn't a good name it really should be like if object is associated with a file that might be a better name for this but you know that would be a lot a lot of text so what this line is going to do is it's going to check if this object is associated with a file if it is which it is it's going to output ok the file is open if it's not and we did something wrong it's going to say Bucky you messed up so let's go ahead and run this and indeed we get ok the file is open so saying all right so when would be the case scenario when the file wouldn't open well for example if you go ahead and you made you know your file object correctly but you forgot to associate it with a file right here then whenever we try to run it it's going to say hold on Bucky you messed up you forgot to associate your object with a file so that is case scenario where we would want to check if the file is open or not and basically in programming well in the real world how it works is this you make sure it's open first and then you write all your code right here so it's a nice little check before you know you just start writing code like this this is probably would be better if we threw inside here you know so if you wanna you know impress your boss or your teacher just make sure your files are open before you start doing a bunch of crap to them or else you know it's going to save you a lot of headaches so with that being said and this is where I just want to stress you guys that there is indeed an optional constructor where you can associate a file with the object instead of putting on two lines of codes and also what you can do is it's a better programming practice to make sure your file is open and by that I mean make sure your file is associated with the object before you start doing a whole bunch of crap to it it's going to save you some time and save your computer a whole lot of headaches so with that being said that's all I have for you guys for the story so thank you guys for watching I don't forget subscribing if they have any questions so check out my forum the New Boston calm slash forum and yeah I'll see you there so thank you guys and I'll see you next video alright guys welcome to your 66th C++ tutorial and in this tutorial I'm going to be teaching you guys how to make a custom file structure to work with your program because whenever you build your own custom program you just don't want to use any file format you know playing off-the-shelf format you want to build a custom file structure so that it makes it easier for your program to work with your files and I don't know what I'm talking about now but trust me you will buy that in this tutorial so the first thing we need is an idea actually before we get started let's go ahead and say that we wanted to make a game like Sim City or whatever where we had a bunch of different players or a bunch of different characters and we wanted to store all the character information and the text file well the first thing we need is of course a text file so go ahead and put of' stream and we'll just name it like the file good enough I guess and we'll just go ahead and create a file called players dot text now remember if this file already exists then C++ is going to look at it's going to open that one but if it doesn't exist yet which it doesn't let me go ahead and pull up my directory see no players that text since it doesn't exist already C++ is going to automatically create one once it sees that indeed does not exist so let's go ahead and the first thing I want to give is we're going to be making a program basically to enter the character information you know say we wanted to build a bunch of characters ourselves well let's go ahead and give the user an ISO prompt about what we want them to do so see out not mmm close but you know not close we'll just go ahead and put enters enter players ID and then you know maybe they have a name for each player and maybe they have like a bank account money or something simple enough and then go ahead and end that line so this is just going to print some text out on the screen telling them what to do so we're going to enter a number a name and another number the first one's going to be the ID number the second one is going to be their name like Bucky and third one's going to be like 48 dollars in their bank account something stupid like that and now what we want to do is we're going to be working with something called an end-of-file marker now before I go on let me say this every file on your computer when C++ opens it's going to look for the end of file marker this is pretty much the end of your file it's I mean no weird complicated explanation it's just a little symbol that goes at the end of your file to tell C++ you know how long your file is whenever it's reading your file and it gets that end of file marker that's where it knows where to stop it's pretty much telling C++ where the end of your file is simple as that now what we can do is we can explicitly enter and end a file indicator and I'll show you guys how to do this later on but basically whenever you hit control hold down control in his e on your keyboard if you're working with Windows this inputs an end-of-file marker and I know it's kind of a weird way to do things because if there was an end-of-file marker button on your keyboard it would be a lot easier to see but if you're working with Windows then hold down control in his E and this puts the end of file marker and so we'll just go ahead and they probably don't know that so we'll just go ahead and put press ctrl + Z to quit the program and you know stop um inserting characters or whatever so go ahead and in that line I know that's a little weird but we need it or this program would just keep running forever so now we need three variables that are temporarily going to store this information just go ahead we'll make the ID number an integer and we'll make the name our string of course and we'll put the money since it has decimal points like 48 dollars and 87 cents we'll go ahead and make a double so we have three variables ID number name and money now what we need to do is we the user want to be allowed to enter this information whenever this program is running so let's go ahead and make a while loop because we really don't know how many characters the user is going to enter and here's what we do remember anytime you want to get information from the keyboard aka from the user use CIN and then the first thing they type in is going to be stored in the variable ID number the second thing they type in is going to be the character's name and the third thing they type in is how much money the character has so the user is going to be able to type characters information you know maybe five different character informations and then we want to be able to store in a file so this basically the user is going to be able to type in as many characters as they want so this loop is going to be true as long as they don't get to the end of the file and how do you know you get to the end of file because of this weird control-z thing so basically whenever the user enters information we now have an ID number a name in some amount of money so now the only thing we want to do is we want to insert it into the file so of course remember just like before in the last Oriels we write the file object and this is pretty much a synonym for players text so they can be used interchangeable they can't be used interchangeably but whenever you're looking at it just assume that this means player is a text so anything we insert it just gets directly inserted into the file players out text because that's the file associated with object right here so the first thing we want to insert is the ID number and then just so it looks nice and pretty just go ahead and insert a little space and then the next thing what do we have a name and then a little space after that and then the last thing is money and line and let me make sure I got number space namespace money and line okay so it's good go so basically well let's go ahead and run this program and see what we get it says all right enter players ID name and money so let's go ahead and make a couple players for this you know Sim City social community game whatever that game were making so the players ID is going to be like 1 and the players name is going to be like Bucky and the money I have is like $65 and 47 cents go ahead and press Enter add another character on the ID is 2 the name is Sara and she has 43 dollars and 21 cents and let's make one more 3 is Sofie and she has two dollars and 54 cents now let's go ahead and press well we can just go ahead and press ctrl-z right now and sometimes you have to press ENTER and then your program is going to stop sometimes you can just hit ctrl Z and it send a file sometimes you need hit ctrl Z enter so anyways I hit ctrl Z that signified the end of the file and of course when I got to the end of my file I couldn't insert anything else so my program quit as you can see right here so now if you go up to your documents you can see that you have a txt file created called players text so let's go ahead and click that and you can see at the well basically it inputted exactly as we input it does that make sense no well too bad you can see that it wrote to the file exactly what we wanted to exactly in the format that we wanted to so basically what was going on is this we first created a file that we open and whenever we open it we have access to that file we then gave the user a nice little prompt to show them how to input the data and then made three variables so we could temporarily store the data now the user was allowed to fill in the variables ID number name and money and whenever we had those variables populated with values we just stored them in a file using whatever format we wanted to in the format we wanted to store min was the ID number space name space money and then once you got one character or one player inserted just go to the next line and do it again so that way on the next line it was ID number name money on the next line ID number name money so that is how you can have you know a way of storing data into a file formatted how you want it so you're saying all right why would I want to format it like this well maybe you wouldn't but whenever you know the structure of how your file is formatted that way whenever we open the file to read all the information in we know what format it's going to be and so that's why you want to create custom file structures because custom file structures make it easier for your program to work with files if they know where the data is going to be and also what type of data is going to be there for example in our game we knew that that first row was always ID numbers that second row was always names in that third row was always and by the way row I mean column that third column was always the amount of money so I mean it just makes it really easy to program this way so that's all I have for you guys for this tutorial I know this was kind of weird with this control-z thing I probably should have made it without it but hey you guys learned something new I guess so thank you guys for watching don't forget to subscribe and I'll see you guys in the next video what is going on guys welcome to your let's see sixty seventh C++ tutorial and in this tutorial I'm going to be teaching guys how to read custom data so in the last story what we did is let me scroll to my desktop watermelon we created this players text file and what it did is basically allowed us to create our own custom file structure and what we did is we were making our computer game with a bunch of different players we gave them an integer as the ID number a name which was a string and their bank account which was of course a double so now we have all our data right here and it's laid out in a very specific way no other program could really understand what this data is used for except our program so now that we have that data we need to be able to read it specifically in our own custom way so it's a little bit different than writing it for a couple of reasons which I'm going to be talking about so the first thing I want to stress to you guys is you can't use o F stream Oh F is for outputting data to a string for example when you have text and you want to output it to a file or write it to a file whenever you want to read data in from a file you need if' stream this allows you to take data from a file and read it into you know the computer's memory or whatever so it's the opposite of Oh F stream Oh F is for writing that a to a file i F is for reading data from a file so then you go ahead and create your file object I'm just going to mine the file and then of course is a constructor optional optional constructor you can take the name of that file so players dot text was the name of that file you can either create the text file document or excuse me what am I going to say the file object on one line of code or break it up into I always like to put it on one line of code just like when we were writing to a file so aside from that what we're going to be doing is we're going to be reading the data from that document so remember that document have three pieces information in it on each row it had an ID number a name in the amount of money so let's go ahead and make variables to hold that data into ID and then we'll make string name to store their name and double money to store their you know bank account information so basically how we're going to do that is this we're going to create a while loop in the wallet you can loop through each piece of information whether it's their ID number their name or their money and it's going to store it in a variable and whenever we have that information stored in the variable is we can do you know whatever you want that we can load it into our computer game we can just go ahead and print it out on the screen we can go ahead and send it to database on the internet but basically what we have to do first is take that data from the file and we need to store it on variables in our program so I want to talk to you guys about how we're going to do this remember I said in the last tutorial that every file has end a file marker and C++ pretty much is going to run this program until it gets to the end of file marker and then when it gets to the end it's going to return something called a null pointer so let me go ahead and actually code this and then I can explain what I'm talking about so just like before whenever we were you know whenever you use like cin to get information from the keyboard and then you could store it in variables like this well now we're getting information from the file so we go ahead and type the file and that's where the information is coming from and we're going to store an ID the first piece of information and the second piece of information we're going to store name and the third piece of information we're going to store in money so it's basically going to loop through this while loop and look at the file each time and every time it gets the new piece of information it's going to store an ID name and money now let me say this whenever you're working with files there's something called a file pointer let me go ahead and open my document again and I could probably show it to you guys really easily or it's a watermelon players so whenever you're working with files you have something called a file pointer now the job of this file pointer is to keep track of where in the file C++ is working with so what it's going to do is this file pointer let me go ahead and skinny up my program a little bit is going to start at the very beginning and by the way the end of file pointer is what right there where my cursor is but anyways your file pointer always starts at the very beginning what this loop is going to do right now is it's going to read the first piece of information so it's going to see right there that's the first piece of information that number one right there is what I want to store an ID so next it says alright this next piece of information store a name so it's going to scroll the file pointer is going to go to this next piece of information and it's going to see this one right here Bucky should be stored in name and then it's going to say all right now the next piece of information which is this right here I'm supposed to store this in the variable money so that's what's going to happen the first time this program loops through so the next time it loops through the file pointer is going to be right here so that's why we didn't have to change any line of code right here because we're working with the same object yet it knows the next piece of information is this too because the file pointer the next time this loop runs is going to be at the beginning of the next line or at the end of this line pretty much the same spot so that is how the file pointer is going to be working and by the way it actually is called the file pointer so you know I'm not making that up so that's why this loop is going to run fine each time so now that we have the correct pieces of information stored an ID name and money we can just go ahead and if we were making a game or something we would want to load them into the game but for now let's just go ahead and print them out on the screen so see out / now ID and then go ahead and I'm going to make a comma-separated list instead of you know spaces because you know if you're working with Excel well nevermind oh they use comma separated list but anyways I just like how it looks so the next piece of information is name and I'm just going to add a comma right there and lastly what is it money so after this I'm just going to go ahead and end that line and whenever you run this program it should work just fine so what it did is it read that file from the txt file one Bucky sixty sixty five point four seven and it did what we wanted with it in in this case what we wanted to do with it is just output it on the screen so we set alright now that we have the information output the ID and then a comma and then Bucky and then the comma and then money and then end of the line so it goes to a new line so then where this is working in the file is it's at the end of the file so whenever you run this loop again the next idea jumps down to is number two it runs the entire loop it's at the end of that line and then whenever you run this loop again it jumps down to the ID number three and it runs that line of code and how this does this while loop know when to stop because whenever the end of file marker has been reached C++ knows already without us having to type any extra code that a null pointer is returned basically it changes this boolean to false so whenever this is working this is true whenever it gets to the end of file C++ already knows that this loop should be false we don't have to explicitly you know write the if statement in here to check it or anything it's one of the cool features of C++ it automatically knows when to end so that's one cool thing that we don't have to worry about another cool thing that we don't have to worry about is whenever we're working with this if' stream or OS stream object whenever the file reaches the end of the file and this goes to false this object is going to get deleted automatically in the Deconstructor remember when we talked about constructors and deconstructors the D constructor is going to call the closed file method so remember like in the first file tutorial I told you that told you guys that you need to close your files in order to free up resources well with this I have stream constructor or excuse me D constructor is going to do is as soon as this file object gets deleted this file is going to close automatically so that's two things we don't have to worry about whenever we get to the end of file this is going to go to false in the loop is going to end automatically and also whenever it gets to the end the file the D constructor is going to close the file automatically so I don't have to explicitly write the file dot closed so pretty much everything is handed to you you just got to remember how to use it C++ made it really really simple to work with files if you really think about it you don't have to do all the background stuff so there you go that's how you write and read a custom file and again your file structure is going to be different depending on type of application you make but that's the basics of it so thank you guys for watching don't forget subscribe I know you guys probably have a lot of questions just ask my on my forum the New Boston comp forum and I'm going to go to McDonald's get a extra large milkshake and you well check out my next video so think guys watching and I'll see you then alright guys welcome to your 68th c++ tutorial and these next couple tutorials are going to be a chain of tutorials I can't teach you guys what I'm going to teach you in one tutorial so it's probably going to be like a three or four part series but anyways what I'm going to be teaching you guys is this I'm going to be building a really cool program showing you how to work with files and by the end of these tutorials you guys are going to be a pro on how to work with files so basically what we're going to be doing is we're going to be pretending we're making a computer game now in this computer game we have a character and this character in his own little world is going to come across a bunch of different objects some objects have no effect on them whatsoever zero effect on his health or is you know happiness whatever you want to call it some objects like ninjas meth and dirty needles they harm our character so they're going to you know have negative 54 energy or what to say it's like energy or something now some objects like a fruit a soda and candy help our character out so they're going to give them positive energy so as you can see we have a file with a name and the effect that it has on our character's energy so we're going to be building a program just to print out these different types of items and groups for example we're going to have the user press one if they want to print out all the plain items like a shoe a pencil and chair press two if they want to print out the helpful items like fruit and soda and candy and press three if they want to print out the harmful items like a ninja meth and a dirty needle now we'll have them press four if they just want to quit the program altogether and you know go watch YouTube videos so that's the basics of what we're going to be doing we're going to be incorporating a program with a file and it's going to work beautifully together but like I said it's going to take more than one video so just be prepared for that so let's go ahead and start coding this baby right meow so the first thing we want to do is we want to give them a menu to choose from now this menu is going to be one two three four depending on what they press we're going to output the appropriate items so we're going to want to store this variable either 1 2 3 or 4 in a variable so just go ahead and make will store this number and variable named what they want now this will be equal to one two three or four so now what we can do is we can just take that variable what they want and we're going to set it equal to a function in order you know to get the number from them so we'll just name this function get what they want now we didn't build this function yet and this obviously isn't a built in function on C++ so we need to go ahead and build it right now so what I like to do actually is whenever I'm building a big program that's going to be working with a lot of functions above each function well I'll just do with main first I like to leave a comment just the function name like a main function and you guys may be like alright why the heck do you want to do that well if you notice the comments are a different color and it makes it really easy to find functions whenever you're scrolling through like three hundred three thousand lines of code so you guys might be like alright that's kind of dumb but trust me do it it's going to save you a whole bunch of headaches in the future so we're going to be building this get what they want function so the first thing I'm going to do is get what they want function and I probably spelled it wrong yep but you know good enough so now remember this function has to return an integer that's going to be either 1 2 3 or 4 so our turn type is going to be integer now the name is get what they want so just go ahead and copy that and paste that and it's not going to take any parameters we don't have to give any information into it we just want to get information back from it so that's why it's not going to take any parameters so now what we want to do is we need a variable to temporarily store 1 2 3 or 4 so we got to make an int variable and we'll just name this choice name or whatever you can name it X if you want really doesn't matter so now what we want to do is we to output the their choices for them so you know they know whether it enter one two or three or four so just go ahead and make four different see out statements we can make it all in one statement but it would probably look cleaner if it's just four different statements so in the first one we'll just put enter one for just plain items and you probably want to put each of these on a new line so just copy this three more times copy and we'll go ahead and write enter 2 4 2 can be let's say helpful items and this will be the you know candy the soda is that really helpful for a kid I don't think so but in this game it is and three will be for the harmful items and this will be like the the ninja their dirty needles and the website put oh yeah meth definitely harmful for a kid and four will just be like quit program so whenever they press for the program is going to quit so now what we want to do is we want to allow them to input of course one of those numbers so CIN that's how they get information from the keyboard and whatever number they enter it's going to be stored in the variable choice now all we need to do is take that variable choice and return it in our function so whenever we return choice it's going to store that number and what they want so now this could what they want function basically gets a number from from the keyboard and it stores it in a variable what they want so now we have a variable either 1 2 3 or 4 but we didn't do anything with that variable yet and what we want to do is since this program is going to keep running until they hit 4 we want to throw pretty much our entire program inside a while loop and this while loop is basically going to say ok keep running this program until they hit the number 4 so we're going to say all right while that what they want variable is not equal to the number 4 keep running this program and of course at the end of this at the end of this while loop well let me think actually no okay I'll save that for later on but basically what I'm going to be doing is this I guess I can throw it in right now at the end of this while loop we want to give them another opportunity to you know get what they want to enter another number so go ahead and copy this and well I guess I can show you guys what's going on right now basically this program is going to run and I didn't prototype it always remember to prototype your functions ladies and gentlemen and whenever your prototype something just copy the header and paste it at the very top and that way whenever your program comes across it like it did right there um it's going to know what it is so let me show you guys what's going on so far well the very first thing that we did is we ran this program and it called up this function right here now once it got that function it pretty much took a number from one to three or four and stored it in the variable what they want and we said all right keep calling this function in making equal to store to what they want until they enter four so whenever they run this program they're going to be able to enter one it's going to do something too it's going to do something three it's going to do something they can enter three 100 times if they want but as soon as they enter for the while loop is going to end and the program is going to quit just like that so we have the basic shell of the program right now we basically are getting a number from them and we're going to keep getting a number from until they enter four so now with the basic shell done the only thing that we need to do now is whenever they enter one handle that one appropriately and show all the plain objects whenever they enter to handle that appropriately and show all the helpful items whenever it ends will enter three show all the items that are harmful to the character in now that we now have the basic shell we can move on to that but we can in this story because if I do I'm going to run out of time so copy all this code down make sure you know how this menu function works and also make sure you understand why how we keep looping through this function until they enter the number four and by the way as soon as they enter number four this while loop is going to be false and it quits and as you can see whenever it quits there's no more quote there is no more code after it so the main function ends in our program stops so once you guys understand that you're ready to move on to the next tutorial so thank you guys for watching don't forget subscribe and I'll see you guys in the next video alright guys so hopefully you watch my last tutorial number 68 and now you're watching the 69 tutorial and in this tutorial we're going to be finishing up the program that well I don't know if we're going to be finishing it but we're going to be continuing the program that we started in the last oriole so in the last tutorial what we did is we basically built the main functionality for our program the only thing that we didn't do is handle the other items except for four so I already told you guys that what this loop does is it tests this variable what they want and if it's equal to one it should print out the plain items if it's equal to two it should print out the helpful items if they enter to the number three then they should print out the items that are harmful to the character so what we want to do is we want to test this what they want variable for one two or three now what we can do is make a bunch of different if statements but remember I told you guys whenever you're testing a single variable for multiple values it's better to use a switch statement now a switch statement takes one parameter the variable what they want and it tests it a bunch of against a bunch of different cases so let's go ahead and finish this by we need the curly braces right here and inside the curly braces of the switch statement we write all those different cases so we go ahead and we first write in the case of one what do we want to do and we're going to be wanting to display these items and we can write all the code right here but since we're going to be displaying the items multiple times it's better to build a function later on so let's go ahead and just again I didn't build this function yet we're going to be building it later on but let's go ahead and build a function called display items and whenever we enter one we're going to pass in the parameter one now display items like I said is going to be a function that takes one parameter depending on what parameter it takes it knows what items the print out so whenever we display items with the parameter one it's going to print out the plain items so of course remember we add break after every case so it doesn't go to the rest of the cases and let me just go ahead and copy this two more times so in the case of two and in the case of three so if what they want is equal to two then we want to display items with the parameter two if they enter three that means that they want to print out the harmful items so we'll go ahead and write a function display items that takes the parameter three now check it out this main function is done completely we don't have to do anything else to this main function the only thing we have to do is build this display items function pretty cool huh so let me go ahead and come down here and the first thing like I said that I like to do whenever I'm building a function is add a comment now I'll just go ahead and put display items function now this function it's only going to print out stuff on the screen that's his only job to display items so let's go ahead and make a void as a return type we're not getting any information back it's just going to print out something it's just going to you know do the dirty work for us so it's void we're not asking for anything back in return we're just asking it to do something so now let's go ahead and write display items and of course remember it needs to know what items you want one two or three it basically needs to know what choice did you enter one two or three so we're going to be passing it in an integer parameter just like that now well the first thing I want to do before I continue is go ahead and prototype my function and remember to prototype your function one last time go ahead and copy the header and paste it right above your main and the reason we prototype functions one more time is because whenever we come across it right here in our main program it knows that it's a function that we made later on right down there hopefully you guys watch my series before and you should know that but anyways let's go ahead and build this display items function so the very first thing that we need to do is we need to have access to that file where all the items are and remember this is the file right here with all the items in in you know whatever this is the effect of energy on our character or whatever so remember we already know how to open a file to gain access to it and that's through an if stream object and by the way before I even finish typing that make sure you have included your F stream this is pretty much the header file that allows you have access to the files so in order to read information from a file we need to make an if stream object and just go ahead and name your object you know objects file by the way I named this file objects so that's why I'm in this object file and of course we can put this on two different lines but it takes the optional constructor of what file do you want to associate this object to and we want to associate this object with a objects dot txt file that's the text file that I just showed you guys now after this we need to make two variables the first variable is going to store the name of the object and the second variable is going to store you know the power or the energy whatever you want to call this thing I'll call it power so the first variable is going to be a string variable and it's going to store the name of the object the next variable is going to be a double variable and this is going to store the power of the object so now what we can do is the first thing we want to test is what choice did they enter so we're going to be making a bunch of different if statements we can make a switch statement but I think if will look a little bit neater so we'll say all right if the choice they entered which is X is equal to 1 then check it out that means that they wanted to display the plain items in other words they want to display the items that has zero effect on our character so if the choice they entered is equal to 1 what do we want to do well we want to go ahead and first here's what we're going to do we're going to loop through each object we're going to loop through this one this one then this one then this one then this one each time we loop through we're going to want to check if the power is equal to zero if the power is equal to zero then we're going to want to go ahead and print it out so it's going to say all right loop through this one print it out loop through this one don't print it out don't print it out print it out print it out um so that's what it's basically going to do so the first thing we need to do is loop through each object and we in order to do that if you remember from let's see I want to say two tutorials ago we can just go ahead and make a while loop and in this while loop just go ahead and write come on there we go I was waiting for it to pop up go ahead and write your object file and then go ahead and we're going to store the first thing and name and we're going to store the second thing in power and this is going to loop through as long as your file is open so it's going to say all right loop through the first thing stored a name and store it in power so now what we want to do is we want to check all right whenever you loop through an item and the power is equal to just go ahead I don't want to add that space if the power is equal to zero then go ahead and print it out so see out name of the object and then we'll just go ahead and add a little space and then the power and then we'll go ahead and end that line so basically we're going to be looping through this whole file whenever it gets to item where the power is equal to zero print it out on the screen now let's go ahead and copy this two more times you never say all right remember X is the choice that they entered so if they enter the choice of number two then they want to print out the helpful items just like that so whenever they want to print out the helpful items we know that the power must be greater than zero because remember a helpful item is like a candy or a soda where the power is greater than zero so what this is going to do is whenever they enter the choice to print out the items that have a power greater than zero and whenever they enter the choice 3 print out the items that have power of less than zero and these items are you know a ninja meth and dirty needle all those items that are harmful items have a power of less than zero right like that so basically our program is complete this is ready to run and I know you guys are just itching for me to press this build and run button and see this program go to work but I'm actually going to be doing that in the next tutorial because first I want you guys to watch one of my other videos kind of sucker you into that one and also I'm going to be showing you guys that it does indeed run perfectly I actually in between these videos I'm going to check for errors and make sure I didn't mess up anything and I'm also going to be talking through you guys one more time to clear up any you know confusing things that or any questions any guys might have so thank you guys for watching I cannot wait to press this pun so I guess you guys are going to have to see me press it in the next tutorial so thank you guys don't forget subscribe and I'll see you guys next tutorial alright guys welcome back to your 70th tutorial and this story really isn't tutorial at all we're just going to be running the program that we built in the last two tutorials and I actually did check for errors in the last video and this program is built perfectly who woulda guessed and so it's ready to run so let me go ahead and press this build and run and show you guys how it works so the very first thing it does is pop up a menu and it gives us a choice press one to print out plain items to four helpful items press three to print out harmful items and whenever you want to create the program press four so let's go ahead and print out one and this is going to print out the items that have no effect on our character so press one go ahead and hit enter and it's going to print out chair a shoe and a pencil all with zero effect on our character so now let's go ahead and let's get down you know three or something hit three enter and it's going to print out ninja meth and a dirty needle so now let's go ahead and print two and whenever we hit two to print out the helpful items is going to print out fruit candy and soda and now let's go ahead and press four to quit the program and our program is going to end with execution time of 49 seconds how awesome is that so one thing that I want to do because it's just going to annoy me is I want to add a new line right there and right there so now whenever you run the program it's going to you know it just makes everything not bunched up in one line so if you go ahead and hit two you can see that you know it makes it a little bit better so again there's a lot of different formatting things that we can do but you know I just want to make sure it wasn't bunched together so to print out all the helpful items um if I go ahead and you know hit three it will print out are the harmful items yada yada yada so basically I wanted to show you guys that this program does indeed work I wasn't biessing you and this is how you can build a program that works awesomely with a file in this case the object file or the objects text file so let me guys let me talk you through how this program works one last time the very first thing I want to mention is whenever you're building a program takes a bunch of different functions make sure to prototype your functions first and foremost if you don't prototype your functions like this and try to run it you're going to get an error message because it's going to come across this function and it's not going to understand what it means so that's why you need to prototype your function so once you have your functions prototype let me run this get that error message out of the way now that you have your function prototype I'll tell you guys how this program works the very first thing we wanted to do was display a menu to the user and we wanted them to enter a number 1 2 3 or 4 depending on their menu choice so what we did is we built a function to display that menu name get what they want and we took whatever they entered and we stored it in variable called choice and what this did function did is it returned that variable choice so it basically stored that number either 1 2 3 or 4 in the variable what they want because this number tells us what they want so after that we took that number and we first made sure it wasn't equal to 4 because remember 4 means they want to quit the program so whenever they entered for this while loop ended in the program quit so what this wallet did is said alright if they enter any number besides 4 go ahead and run this code right here because that means that they want something if they enter 1 it means they want plain items 2 helpful items 3 harmful items so I said alright test this variable if they enter 1 2 or 3 if they enter 1 call this function in display items with the parameter 1 if they enter 2 it means they want helpful items so we're going to call display helpful items and if they enter 3 we're going to pass in 3 on this display items function so you're saying all right so the display item function obviously displays the proper items to them so say we passed it the variable 2 whoa it calls the display items function with a parameter to it basically Scrolls down here and cause display items now remember display items it just prints out something on the screen it doesn't give us any integers or strings back so we made that void now whenever we pass then 1 2 or 3 it treated that variable as X so X was pretty much your choice 1 2 or 3 so the very first thing that we did in this function is we open that file because I mean all the crap that we needed was inside this file so we open that file and then we made two variables we made a name variable to store the name of the object and we made a power variable to store how much power that object had whether it's 0 negative or positive we then tested what choice they wanted remember if X which is now the choice is equal to 1 then it means they want to display the items with no power the plain items whenever they entered the number 2 it means they wanted to display the helpful items and helpful items just had a Power greater than 0 so that's why we printed out the objects with the power greater than 0 whenever they entered the number 3 it means they wanted to display the harmful items the items that hurt our character so said all right we're going to test this power variable and any object with a power variable that's less than 0 go ahead and print it out so that is how our program works and here's what I'm going to ask one of you guys to do you guys probably want all the source code for this so actually what I'm going to do is I'm going to go ahead and copy this and post it in my forum under the c++ section so if you guys want just go ahead and sign up actually don't even need to sign up for my form but I would prefer you did sign up for my form go look in the C++ section and I'll post all the source code here so if you guys you know are getting an error in your program whenever you're working along you can just go ahead and copy my source code and it's all there for you guys so thank you guys for watching so much hopefully you understand how this program works if you don't understand then don't flip out all you need to do is go ahead look at the source code and once you see it all together um you guys can understand how it's all pieced together so again one last time this is how you build a program that works perfectly with a file just like this and with that being said I want to say this a lot of well in this tutorial I showed you guys how to have the user you know input a number and print out all the helpful items or harmful items but in whenever you're developing a game instead of just printing it out on the screen you would want you know whenever your user comes across a helpful item do you know make them get that much energy or whenever your character comes across a harmful item have them you know take that much energy away from your character or whenever your character comes across than item like a building or a chair or a shoe it has no effect on the character so aside from printing it out we would do something different in this line of code right here but that's basically um your very first glance at how games and programs work of files in a useful program so I'm glad I could teach this tutorial finally make a program that's useful instead of teaching guys just the core concepts I know a lot of you guys were complaining that I was just teaching the concepts and you guys never really got to see how a program was put together so hopefully here's a nice little look at how it works so thank you guys for watching one last time thank you guys so much for subscribing and I'm excited to move on to the next topic so hopefully we're done working on files at least for now so thank you guys for watching and I'll see you guys in next video what is going on guys welcome to your let's see seventy first C++ tutorial and in these next I want to say three or four tutorials I'm going to be covering more about strings now I know that I touched a little bit about strings in we've actually been using strings this whole series but I want to talk to you guys specifically about the string class now the cool thing about these next couple tutorials is there aren't a lot of confusing concepts that you guys need to understand but the string class gives us a bunch of functions that well let me tell you guys this whenever you're building a program and you don't know how to do something that you usually want to look it up in the documentation and if there's you know an advanced function in order to do something it will tell you how to do it but some functions like how to print stuff out on the screen are essential to have in your memory and a lot of those functions that are essential to have in your memory are a lot of the string functions so this is stuff that whenever your program you shouldn't have to look up so in these next couple tutorials I'm going to be teaching guys the core string functions so the good thing is they aren't confusing they take like a minute each to learn the sucky thing is that we do in fact need to learn these because if you don't know them if you do know them it's just going to make program a whole lot easier so the first thing I want to clear up is probably something I should have touched on a long time ago and that's also something that kind of confuses you guys whenever I was working with files you guys didn't really understand that whenever I came to you know a white space that whenever I was like reading data in from a file then and automatically quit reading it in and let me explain you guys what I'm talking about sit whoa Oh easy calf socks all I got cough oh there I go got some milkshake from McDonald's in my throat so say we have a string called Bucky and we want to you know fill in the string with the users data whatever the user enters from the keyboard we want to store in this variable called Bucky so we use the CIN and whatever the enter is going to be stored in variable called Bucky so now we'll go ahead and just print out something on the screen like the string I entered is and then we'll make a little space right there and then we'll just go ahead and write the variable name which was Bucky and in that line well let's go ahead and run this program and I want to clear up a couple things so now we see a blank cursor telling us to input something and we already know that if we input something like tuna it says the string I entered is tuna we understand that much but what I didn't tell you guys and I probably should have told you guys this in like the tenth tutorial but you know better late than never is whenever you enter something like tuna sandwiches are good and you say all right well that's my string of text and you press Enter it only says the string I entered is tuna and that brings me to a lot of a point that I should have covered in either the 10th tutorial in the last tutorial when I was teaching you guys how data is read in from a file whenever you using cin to read data in whether it's from the keyboard the user or a file when you're using c i end the end of the input is determined by the first whitespace character it comes across so for example whenever you run this program and you see tuna sandwiches it doesn't read that whole tuna sandwiches it reads it until it gets to it first whitespace so that's why in the last tutorial whenever we came across you know a newline character or a whitespace that's when it stopped and that's when it finished reading in the data so hopefully you guys understand cin only reads one small piece of data at a time so now that you guys understand that concept let me talk to you guys about another concept and that is well what happens when you do want to read an entire line as one string well say we go ahead and lesson name our string something else besides Buckey let's name it string X whenever you want to read an entire line of data here's what you do you go ahead and write the function get line and go ahead and write CIN and just go ahead and write X and now let's just go ahead and you know print this out on screen real quick and line and now what get line does is instead of the end of input being determined by a whitespace character like a space the end of the input is determined by a new line character so get line is going to wait till we have a new line in other words when you're working with cin which means input from keyboard it's going to wait until we press Enter or basically when we're done typing text on the line so now when we put tuna sandwiches are good and press Enter it's going to output tuna sandwiches are good and this entire third thing is the string that's going to be stored in X so again what I want to stress is whenever you're working explicitly with CIN it reads one small piece of data whenever you want to read an entire line you want to use get line sorry I still got that milkshake stuck in my throat so that is the difference between CIN and get line and how the end of the input is determined by a white space or a newline character so that's not only going to help you a lot when you know getting information from the user but also whenever you're working with files that's how it read the information I probably should have told you guys that before but hey like I said better late than other never there you go okay let's slow down for a second Bucky and I gather your thoughts and all right I'm gonna go now so now I want to talk to you guys about additional ways to create and copy strings so aside from having you know string Bucky equals Yaya oops yada yada yada and while this is a valid then this is the way we created strings before I want to tell you guys about an additional way to create strings from the string class say we want to create a string named s1 we can go ahead and pass it in a constructor of a string like hampster just like that and now hamster is going to be equal to s1 again like I said just two different ways of doing the same thing but why do we need to know this because whenever we're working at a company and someone creates a string this way we don't you know think it's something totally different or some class that they made up we know that you know don't freak out it's just the same way of creating a string so if we want to create a blank string we can do something like this and let me go ahead and create another blank string because I'm going to be showing you guys an example later on so anytime you want to copy a string you can do so in one of two ways the first way which you guys probably could guess is you can set string two equal to string 1 which is hamster now this is a valid way of copying the string but some people also want to use a function from the string class and that's called assign now assign isn't really a good word they probably should just named it copy but it does the exact same thing and that say you want to have s3 and you want to have this you know actually we have it right there it already pops up for us assign string one these two go with you know with exception of being string two and shrink three these do the identical thing each of these functions copy this string to this variable right here so again just to prove it to you guys let me just print out all these on the screen Oh print s1 s2 and s3 and just go ahead and end that line and whenever we print it out we can see that all these things hamster hamster hamster do the exact same thing so again what this line of code does is it's just an additional way where we can go through the string class and we can create a string using the constructor and what this does right here this assign is basically an alternative to copying strings so with that being said um I want to talk about one last thing and hey I guess again okay the last thing i want to talk about in this tutorial and i'm probably going to go over 10 minutes and i hate making videos over 10 minutes what i do is strings are arrays of characters they're not like arrays of characters that are not similar similar to arrays of characters strings are indeed arrays of characters so let me go ahead and make a string called s1 and i'll set it equal to oh em gee WTF BBQ good enough so now i want to stress that anything you can do to an array you can do to a string so let's go ahead and see out something like s1 and say we wanted to output one of these characters and these characters are elements in the string 0 1 2 3 so this w is s1 3 well in addition to you know having the explicit index the string class also has an ant method to say alright if we put 3 right there it's going to look in the third element in the array and it's going to find what character is at that location so it's you know a little easier to tell to someone who's like just learning programming using the app function is a little easier to see then you know using the array indexes right there so let's just go ahead and end that line and print out and whenever we print it out we can see that we indeed get a W so the point of this lesson is I want to stress you guys that strings are arrays of characters and one other cool thing I might as well teach you guys while I have the time is just like an array where we can loop through it and print out each one of its indexes we can also loop through a string so let me go ahead and put int x equals 0 and in order to get the length of a string it has built-in length function so put X is less than oh what's my street name s1 dot length with no parameters and we'll just loop through them one at a time using X plus plus so now what we need to do is just print out on the screen s1 dot at and as a parameter we can just go ahead and type in X because what X is going to do is it's going to say all right it's going to start at 0 remember this is the 0th element in the array and is going to count the length of the string and it's going to loop basically from the beginning till the end and the X is going to go 0 1 2 3 4 all the way until it reaches this as last element so that way whenever we pass X into the parameter for at instead of printing just one character it's going to print the entire string so let's go ahead and build and run this and check it out here's what we printed from before from the last lesson and now here's the entire string getting printed out OMG WTF BBQ so those are some simple string functions like I said before none of these are going to you know twist your brain like polymorphism or maybe working with files are but there's some core functions that we need to learn especially the at the length those are two string functions that you're going to see a lot whenever you're working for a company hopefully you're watching this tutorials in the hopes of you know getting a job or at least working with other people on a game project or something like that you're going to see these functions a lot so you need to know what they are how they work and also some additional ways of creating copying strings so now that you understand these concepts hopefully you memorize them embed them in your brain I want to tell you guys that there are a lot of different things that the string class has to offer aside from you know finding the length of a string so we're going to be covering all those coarse string concepts in the next couple tutorials so have no fear no really confusing topics for now and I want to tell you guys that you're almost to the end of learning beginning C++ we probably only got like 20 more videos to go so with that looking forward to I want to say guys thank you for subscribing thank you for watching my videos and I will see you guys in the next video alright guys welcome to 72nd well we've come a long way c++ tutorial and in this tutorial i'm going to be talking to you guys about some more very useful string functions so the very first string function i want to talk to you guys about is called the substring function now what the substring function does is it takes a big string and it creates a substring out of you know a small piece of it so let me go ahead and show you guys an example it's going to be a lot easier to show you example rather than try and explain it so go ahead and make a string i'm cuming call actually i'm probably going to call all my strings s1 in this story and just go ahead and write something like OMG i think i am Craigie or something stupid like that i don't know create a new string you want and go ahead and print out s1 dot s ub STR this is a sub string function and go ahead and outline and L now the substring function takes two parameters the first parameter it takes is the beginning index or the beginning character remember strings are arrays is pretty much an array of characters so this is 0 1 2 3 4 so on and so forth so let me go ahead and put the beginning character which is 17 and the next parameter it takes is how many characters do you want to go on for so if we put 1 5 it would start at 1 and it would go 5 characters in so let's go ahead and put 17 7 go ahead and run this and we get the word pretty with explanation point 1 2 3 4 5 6 7 actually 0 1 2 3 4 5 6 I don't know it's one or the other but anyways the substring method is basically what character do you want to begin in and this is the seventeenth character and if we count seven characters one two three four five six seven is how many characters is included in the substring so basically the substring function is how to create a smaller string from a bigger string definitely useful whenever well whenever you want to create a smaller string from a bigger string now after this I want to teach you guys about another function and that's called the swap function now this is might be if you're working a lot with sorting lists or how to sort arrays you're going to be using this function a ton what it basically does is it takes one string and swaps it with another string so let's go ahead and put string one and we'll make this one make it something that begins with a a like apples and put string two and what this one does is we'll make this one like beans good enough and what we can do first is just print out the strings to verify that they are indeed working correctly so one and then we'll print out two and then go ahead and in that line so what this line is going to print out apples beans and I'll add a space after this and now what we can do is I want to show you guys what the swap function is and how it works the first thing you need is a string to apply it to and I'm going to apply it to shrink one now go ahead and call swap on this now it always needs to take a parameter and that's what string do you want to swap with it and we want to swap shrink two with it so basically saying are a swap beans with apples and now string 1 contains beans and string 2 contains apples so if we go ahead and print this out again let me just go ahead and copy it and print it out again in build and run the original strings or apples and beans but now it took the contents or values of them and flip-flop them so now string 1 contains beans and string 2 contains apples again this is very useful whenever you're sorting usually you're going to run through a huge while loop and you're going to back all right if this value is greater than this value then swap them if not leave them the same and by the end by the time you get to the end of the loop everything's in a nice neat order so that's your basic of you know how to sort things but again let's go ahead and delete this and again one last time none of these things are really confusing but they're definite functions that we need to know that's why I'm going to be covering this explicitly because these are functions that you should definitely shouldn't have to look up in a you know resource or reference guide these should be function that should be stuck in your brain so the last function I want to cover the in this tutorial is the find function now like I said I want to repeat this one last time strings are just arrays of characters so whenever we're finding a substring what it's going to do is it's going to give us the location or in other words the index of where in the string that is so let me go ahead and make a string again most of these it's going to be a lot easier just to see an example so let me go ahead and make something like Hamm is spam oh yes I am and I actually made that string for a very specific reason what you will see you later on so go ahead and see out s1 dot find a m and now let me go ahead and in that line and you're saying all right so I kind of know what this is going to do already it's going to go and look through your string and find where a.m. is but check it out we have this one right here and this one right here and this one right here so let's go ahead and build and run this and see what when it returns and I forgot to do something and add a lesson and sign right there so let's go ahead and build around this again and it's going to say one so say an R right so obviously it gave me the location of this first one right here because this is the 0th index of this array and this is one so what it basically does is it gives you the starting location of the first found arm first found a.m. I guess that's all I need to say the first found occurrence that's what I was looking for so even though there are three occurrences in this string it's going to loop through and it's only return to you the first occurrence of this so remember that whenever using fine it doesn't give you know 1 and 10 and 19 or whatever the heck these are so saying all right well what if I want the occurrence of the last a.m. well there's another function for that and that's called our find this stands for reverse find you know how whenever you're finding you know a substring such as a.m. and a bigger string is going to start at the beginning and it's going to work a left to right well what reverse fine does is it works right to left just like that and it's going to go right to left and it's going to look for a.m. so it's basically going to give you the last occurrence of a.m. which let's go ahead and print this out and that is 21 so if we can see this is 1 2 3 4 5 6 7 8 9 10 11 12 3456 10 21 right like that as you can see this 21st index in other words this one right here is the first location of the last a.m. so that's the difference between fine and our fine one works left to right and one works right the left so there are some more string functions right there again these string functions our function is that you should not have to look up these are some functions that should be embedded in your programming brain so that's why I want to give them to you guys and hopefully me showing you an example of how they work help you know make them stick in your brain a little bit easier so thank you guys for watching these stories we only have a few more string functions to cover but don't skip over these tutorials because later on when I'm developing games and showing you guys how to work with 3d and cool stuff like that I'm not going to be taking time to stop and pause and cover these functions so if you know you decide to skip these next tutorials and just go straight to game development or whatever you're going to be crap out of luck so there you go thank you guys for watching don't forget subscribe don't forget to check out all my other videos and yeah I guess I'll see you guys later what's up guys welcome to your 73rd C++ tutorial and in this tutorial you will be happy to know we are covering the last string functions so after this tutorial no more string functions for a while so I bet you guys are glad about that so the first thing I'm going to be covering is the string erase function now what this function does it it erases everything from and including whatever element you tell it to so let's go ahead and string I'm just going to make a shrink out string one and all right something like hi my name is Bucky and I love bacon and ham something stupid like that and why not explanation point you know spice things up a bit so let's go ahead and first just print this out on the screen so we have something to compare it to after we change it later on so now what I want to do is I want to let's say I want to erase let's see I want to erase everything from the xx character on so it's going to be like somewhere around here and say this is the xx character right here I want to erase everything from here till the end of the string well we need to use something called the erase function and it's probably already in there right there erase and it takes one parameter what character do you want to begin erasing that erasing it and remember it includes the xx character as well so it doesn't start at 21 and actually erases xx character as well so now let's go ahead and print out the new-and-improved erased string and we'll go ahead and run it and see what it looks like so the original string is hi my name is Bucky and I'll a bacon in ham and the new string is hi my name is Bucky and then erased everything from here on out so that's all the erase function does so now aside from the erase function I guess we can go ahead and keep this and this and this the only line of code that's going to change in this story is this so now that we know what the erase function is I want to talk you guys about another function and that's the replace function so press s1 replace functions already filling in for me all right the replace function takes three parameters the first parameter it takes is what character do you want to begin replacing it and Bucky I already know is the 14th character since this was the 20th character right here so this B is the 14th index the next parameter so let's go ahead and put 14 in there right now before I forget the next parameter it takes is how many characters do you want to replace so let's count one two three four five Bucky is five characters long so we want if we want to erase this entire thing or in other words replace it we're going to start at the 14th character and replace five characters so that's going to replace the entire word Bucky so the third parameter it takes is what do you want to replace it with so now that we have Bucky replaced I think it would be only appropriate to you know add a new name like arm I was just going to enter right there that'd be way too easy like Samuel Jackson and I spelled that wrong but it doesn't really matter so you don't have to replace it with the same number of characters you're pretty much saying all right what do you want to replace and what do you want to replace it with uh so if we go ahead and run this we can see that the original string was hi my name is Bucky and I love bacon and ham and now the new string took Bucky out and added Samuel Jackson so it says hi my name is Samuel Jackson I love bacon in him and he probably does so what replace does is basically takes a certain bit out of the string and replaces it with something else easy enough so now I want to talk to you guys about one last string function and that's insert now what insert does is it inserts a substring into the string but it doesn't take anything out like it did Bucky before so if we wanted to change the strength - hi my name is lucky Bucky and I'll a bacon ham we don't want to take anything out we just want to insert something right after is so what will you do is put s1 as string we're working with the function is called insert right like that and it takes two parameters the first parameter it takes is where do you want to begin inserting it well we already know 14 is the beginning of Bucky and the next parameter it takes is what string do you want to put right there what substring do you want to add into the main string and just go ahead and press lucky and we'll add a space after lucky so it would be lucky space Bucky if we didn't add this space it would be like lucky Bucky one big word but I want my name is lucky Bucky so I'm going to begin at index number four and I want to insert the word lucky with a space after it so don't forget your semicolon and whenever you run this you can see the original string hi my name is Bucky and now we inserted lucky so the new string is hi my name is lucky Bucky and I love bacon and ham so that is how you insert words you know into a string and one other thing I forgot to mention let's see if I can go ahead and ZZ replace just like that usually people use replace whenever they they usually use it in conjunction with fine so remember in the lesser tutorial i told you about find how you can find like all the AMS in a string I think that was an example I showed you guys people typically loop through your entire document and find all instances of something and use this replace function to replace it with this for example here's a great example if you ever use Microsoft Word and it saw that you know you did your whole homework assignment and you saw you spelled the word dictionary with a k' and you typed it like 18 times well whenever you right click it and spell check it it says replace all this is how they made it it just loops through finds all the time you take dictionary weather okay and it replaces it with a proper spelling of dictionary which of course doesn't have a K in it so if you're ever wondering how Microsoft coded that fine and replace these are the methods they used to do it so if you think you know you know Microsoft is a bunch of genius programmers in a program in ways that you can never even learn well that's one of the techniques we already learned that we just you know learn the concept of it instead of applying it in the main program ball they did is they use find if they loop through your entire document found all the instances and each time they found it they called this replace and replace it with a proper string so there you go there's a you know nice low example of when this would be useful in real life so with that being said that's all this well I don't want to say that's all the shrink functions are probably like 200 string functions but those are all the main ones that I want to cover now that we covered all the main string functions whenever your program in games and documents and applications later on and we come across you know a string function we don't have to look up what it means again there are a bunch of different other string functions but these are the main ones that are going to come across in your programming so that being said take take a deep breath and we only got a couple more topics to cover so I am ready for it and to be honest I'm getting kind of tired of learning C++ I'm ready to move on to game development with C++ and 3d modeling we C++ in the fun stuff but hey we got to cover the born stuff before we get the fun stuff those are the rules of life so thank you guys so much for watching and thank you guys for sticking with me for what was it like 73 tutorials already I had super fun I had super you know I'm just going to quit talking right now before I mess up anything else but anyways thank you guys for watching and I'll see you guys in the next video

Channel: Extern Code

Views: 3,098,643

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Keywords: c++, C++ tutorial, C++ programming, learn C++, c++ programming tutorial, c++ language tutorial, learn c++ programming, learn c++ language, c++ tutorial for beginners, c++ programming tutorials, how to learn c++ language, how to learn c++, c++ programming, c++ language, c++ for beginners, c++ tutorials from basic to advance, c++ tutorials complete, c++ programming tutorial complete, c++ programming tutorial for beginners, c plus plus, c++ video tutorial

Id: mUQZ1qmKlLY

Length: 553min 5sec (33185 seconds)

Published: Mon Feb 20 2017