C# Tutorial

well hello internet and welcome to my C sharp tutorial you guys have asked for it and I did my best to cover pretty much the entire c-sharp language in this one video in the description underneath video you'll actually see links to all the individual parts so not only will you be able to jump to whatever you want to learn about but you'll also be able to see every single thing that's covered in this video so I have a lot to do so let's get into it okay so if you are on Windows you no doubt are probably going to use Visual Studio 2015 or 2013 depending upon what you want to use Community Edition and you just go to Visual Studio calm or just type in Visual Studio Community Edition that's what I'm going to be using in this tutorial however if you are on Mac OS X or on Linux you can try out the mono project comm right here and download and give that a try everything here is going to be able to compile on any OS and now let's jump over and let's start writing some code alright so here I am inside of Windows and I'm just going to come in here and open up a Visual Studio 2015 sorry about the zooming some people don't like that and here it is and it's going to be real big here in a second what I'm going to do is I'm going to say that I want to start a new project and specifically I want to start a console application because that's gonna make it easy for us all to see exactly what's going on and focus on coding and click OK and here we go this is exactly what it's going to generate here on our screen so let's just start writing some code we're going to write all of our code inside of static void main right here and let's just start off with the simple stuff comments just two slashes there's your comment and then your multi-line comment is forward slash star and multi-line up above and star and there you go so we got comments out of the way now we're going to be out putting everything onto the console so in this situation I'm going to say console dot if we type in right there is not going to be a newline if we type in right line there is going to be a newline and we can just say a little world and get the hello world thing out of the way and then we can execute that and you're going to see that there it is a little world da-da-da-da-da opened up in the screen don't worry about all this stuff right here all right so let's continue if you wanted to come in here and get input from your user you could say something like what is your name like that and maybe you want to use just right here because we don't want to put a new line after that and then it's so easy to get user input we're just going to come in here well first we're going to say that we want to store a string that's how the input comes in and we're going to store it in a variable name name and just like everything else you can use letters numbers underscores but you should start off with a letter and we're going to say console and read line and that's how we're going to be able to get input and then we'll be able to come in here again and go console and write line in this situation and then if we want to output information in the screen we could just go hello I'm going to put a space inside of there and if we want to combine two strings we can just type in name with our variable name like that now is how simple it is and we can execute it what is your name and I can say Dirk and it will say hello Derrick instead let's get into data types now we have boolean x' and a boolean is either going to have the value of true or false so can vote for example if we want to store that inside of here we could say true or false and that is a boolean characters we could come in CH AR is equal to dot a or whatever and this is going to be able to hold a single 16-bit Unicode character for us and the little lines there is just there because I saying hey you defined this variable but you didn't do anything with it now let's get into all of the different numeric types you have integers with have a maximum number of that big giant number and you can actually get that number do I just going int dot and then max value with uppercase letters like that you have Long's which can have a larger non floating-point number and then once again you can get that value by just going long dot max value and store it over in this variable decimals are actually massively huge and if you need anything bigger than that you could go and take a look at big integers and once again you can get that value by just going max value floats are going to have very large numbers as well however they're only going to have seven decimals of precision that means if you go in here and try to create a float that is more than seven decimals that it is going to cause errors and it's not going to be accurate if you need something even bigger go for doubles for the most part you're going to use doubles anywhere you can see how large they are and they have fifteen decimals of precision which is considerably better there's a rundown of all the major different data types you're going to use being int Long's decimals floats and doubles once again if we want to come in here and combine our strings we could do so with our console and write line and just say something like max int and all the code by the way is available in the description as well and of course it is all free there we go and you can combine not only strings but you can also combine strings with any other different datatype this way and you can see right there I printed that out on screen for me another different data type that is available to you is var and basically the VAR data type is defined whenever the program is compiled and then its value isn't going to be able to be changed so we could say something like bar another name is equal to and it's automatically going to say okay this is a string because the data that you store it inside of there is a string however we wouldn't be able to come in there thereafter and say another and give it a value of two for example that is going to cause an error so this is a shorthand way for us to create a variable based off of whatever we assign to it however remember we're not going to be able to change it to some other data type because this is considered an integer the thing that is interesting is we can come in here and actually get the type for our data type that we have here so let's just go write line and we could say something like another make sure you put double quotes around this another name is a and if you want to format or throw in different pieces of data you can just put inside here you're going to start off with curly brackets and then 0 and then the next piece is going to be squirrely brackets on one we'll get more into that here in a second and then we can come in and get the data type for another name by just going another name and then get type code and execute you can see another name is a string so now let's get into the different math operations we can perform you can see a whole bunch from right here we can add subtract multiply divide this guy right here is a modulus character which is going to get us the remainder of this division and you can see right here how we can increment different values and we're going to see exactly how they work as well as decrement there's the increment and decrement shorthands and you can also see there are additional shorthands this right here would be equivalent to saying I is equal to I plus 3 so this guy right here is just the same as that this is just a shorthand version of the same thing you can see right here if we come in here and add this is actually a remainder operator so you can see it goes in there and throws the decimal point in there as well and you can see right here the way that this is operating with this shorthand notation see right here we have at a value of 0 and you can see it prints out a value of 0 so you might be saying what's going on here basically what it's doing is it's going and getting the current value of I putting that inside of there and then it's performing the addition right here and then when that's the same reason why it jumps up to 2 is it whenever you put the plus plus ahead of your variable like you have right here it goes ahead and performs the addition before transposes it inside air and prints it on the screen same exact thing happens whenever we're decrementing and you can also see exactly how this shorthand notation works right there so that's how you perform your basic arithmetic now let's take a look at a casting and how exactly that works now basically if no magnitude is lost casting is going to happen automatically but otherwise you're going to have to set it up like this so let's say we have double and pi is equal to 3.14 and we're going to convert that into an integer you call this integer pi is equal to you just put little brackets inside of there and what you want to cast it to and then the thing that you want to cast and of course make sure that you always end all of your statements with semicolons that is a requirement so pretty simple if you want to cast from one to the other you just go and put inside of there or whatever you want to cast to as for math functions that are built in there are a whole bunch of them here or some of the other ones and what the heck I might as well just run through a couple of them just so you can see exactly how they all operate so let's go and create ourselves two doubles number one and number two and you can see here we can get the absolute value with this function right here we can get the ceiling which is going to round up the value floor which is going to round down max you're going to send it to numbers it's going to give you the maximum number or the largest number men is going to do the opposite you do the power you can do another round and here is square root you can see exactly how all of those operate right here so absolute value 10.5 could see ceiling is going to round it up floor is going to round it down max is going to give you the maximum value man is going to give you the minimum and you can see the power operation and rounding and square root right there so there are some of the most common math functions you use something else that we'd like to do a lot is to generate random numbers and let's just go and create a random is equal to and you're just going to go new random and then inside of here we can do another console right and let's say that we want to generate a random number between 1 and 10 just be able to come in here and then go Rand dot next and we're going to if we went 1 to 10 we have to go up to 11 right like this if we execute that random number between 1 to 10 and you can see right there is the value of 5 so there's a rundown of a whole bunch of different things we can do math related inside of Seashore now let's go and take a look at some of our conditionals now the relational operators we're going to have available or all the same year very well used two less than greater than greater than or equal to equal to and not equal to and then with our logical operators we're going to have and or exclusive or and not I'm going to show you exactly how they work so let's just come in here and let's go over how if statements work so let's say we have int and an age and let's give it a value of 17 can then come in and go if and we're going to use two brackets here age is greater than or equal to 5 and and this is going to allow us to do two comparisons at once age is less than or equal to 7 then we're going to put in our curly brackets and define what happens if that comes back is true for this to come back is true since we're using and here this has to be true and that has to be true we'll say something like go to elementary school now likewise we continue making comparisons just by going else if and then we could throw in another conditional inside of this age greater than 7 and age less than 13 in that situation once again we could do another console right and instead change this to middle school and then finally as a default if you get through all of those we can say else console right and we could say go to highschool and there you go that's exactly how if-else F and else work as well as the relational operators and the logical operators when it's the example of how the logical operator or works we could also come in here Kengo if age is less than 14 or age is greater than 67 could come in here and say something like you shouldn't work that's not a political statement right there that's just based off of retirement ages and when it's legal to work in the United States anyway all right so there we go and you can see that this is only going to come back true or this is going to come back through if either this is true or that is true and of course we could use the exclusive-or which is going to only come back if one of them is false and one of them is true but this was the one you're going to use most of the time another thing we can do is go console right and just to demonstrate how not works not true it's just going to take whatever you have here and it is going to give you the absolute opposite of it so we can put not true for example right like this and if we execute it you're going to see not true is equal to false also take a look at the ternary operator and it's going to allow us to assign a value based off of a condition so we'll put a boolean in here but this could be anything this could be an integer or double or anything and we're going to say if age is greater than or equal to 16 I'm going to put a question mark inside of there then we'll put true and then a colon and false basically what this is saying is if this value or this condition comes back true we want to assign the value of true to can drive if it comes back as false we're going to assign false to it like I said we could also come in here and do something like integer and then assign some arbitrary number that is how we would like to work with this instead but that is how the ternary operator works inside of c-sharp another condition that we can use is the switch statement yes we have switch statements we could say age come inside of here and we're going to be able to go case 0 like this and then in the case that age has a value of 0 we could go console right and we could say infant and you're going to have to put your break statements in here to jump outside of there otherwise you're going to get errors you're also going to be able to come in and stack these up so let's go case and then we could also check case two and in that situation we type toddler out on so if the value of age is either 1 or 2 it's going to perform this operation that's inside of there another thing we could do is this isn't specific to switch statements but you can use go twos inside of Seashore do something like go too cute and then we could jump outside of this like this and then type in cute the colon like that and this would jump completely out of the switch statement and we could say something like toddlers are cute or something like that that is how go-to works inside of there you can see there you are there's a label jumps to that hopefully you almost never use that because go-to statements can cause major nightmares and then finally of course we're going to be able to come in and find a default situation if nothing else matches and in that situation we could just say child and then through our break statement in there you go that is how switch statements work if ternary operators as well as go-to now let's jump over and take a look at looping now with looping we're going to continue executing statements as long as a condition is true so in this situation we're going to create an integer here give it a value of 0 because we're going to need a value that is going to increment over and over again and I'm just going to call this into I just to keep this nice and simple let's first talk about the while loop and in this situation we're going to continue looping as long as I is less than 10 I could however come in here and say if I is ever equal to 7 in that situation I want to do something different I'm going to increment the value oh I always have to do that if you ever ever have any sort of errors with your loops there probably have something to do with not incrementing when that situation what we're going to say is continue so if I is equal to 7 what we want to do is we want to increment the value to 8 right here I is now going to be equal to 8 and then we're going to say we want to continue with our loop which means we're going to ignore everything that comes out right here we're going to jump back up to the loop and then continue working with what we got right here we could also come in and say if I is equal to No mine in that situation we can use our break statement again which is going to jump us completely out of a loop no more while no more check-in anything we are all done and if I is not equal to seven or nine we could do something like this if we want to only be able to print out odd numbers we could say if I remainder of two is greater than zero well in that situation we want to print out our value of I and do it right like that and then of course we want to make sure that we increment I before we leave our while loop so this is going to come in here the reason why this is only going to print out i if it is an odd value is here if we would take like a four and then do modulus of two that is not going to give us a remainder so we're checking for a remainder and the remainder would only occur if it is in odd number and that is the reason why only odd numbers are going to print that situation if we go and execute this you can see it prints out one three and five right there now the other looping operation we're going to take a look at we're going to take a look at all of them but we're also going to take a look at two while and do-while basically going to be used instead of Wow whenever you want to guarantee that you are going to definitely go through the code in the loop at least once before you check if you should continue cycling through the code inside of the loop and this is actually quite useful let's say that we have a string that we have the name of guess and we want to cycle through this loop and consider or continue getting input from the user until they guess the proper number so we can come in and go console and we can say something like guess a number like that we could then go and get the user input and store it inside of guest by going console read line just like we covered previously and now what we're going to do is the while part is actually going to come after the do part so you can see right here this code is definitely going to be executed at least one time because after we go through it the first time we're then going to say not guess equals and this is how we check for equality with strings so we're going to put 15 inside of there which is a string and we're going to come to the string that was input here by our user so what we're saying is while gas is not equal to 15 we want to continue executing this loop over and over and over again and this is how we check string equality by the way is with the string and then equal sorry like that we can execute it and it's going to say guess a number and we can start guessing numbers until we get to 15 and then we know that we got the right number there's an example of do-while now let's take a look at the for loop which is basically going to allow us to put the iterator and all of its initialization all in one place so we're going to go for we're going to find the datatype for the guy that we're going to need to be iterating over and let's say zero then we're going to define exactly how long or the condition in which we're going to continue execution while I is less than 10 and then we're going to come in here and we're going to say how much we're going to increment each time and you can of course increment this by 2 or 3 or 5 whatever you want to do doesn't matter then we could say something like let's say we want to do similar thing with what we did before we could say if I assign to greater than zero so we're going to check so that we're only going to print odds out on our screen again and we could say console.writeline right like this and then put I inside of there execute it and I wouldn't put I inside of that would I do wrong I put I inside of quotes no big deal got rid of that execute it and we can see that it only prints out our odd numbers so that's how the for loop differs for it and we also have another one which is known as the for each loop and we're going to see more of this later basically what it's going to do is it's going to cycle through every item in an array or a collection and a string is actually a collection of characters and to do this let's go and get and create ourselves a string and let's just call this random string it's equal to and now we'll be able to use the for each by just typing in for each no space we're going to define the data type that we're going to be pulling from this is a string which is just a bunch of individual characters so we're going to be getting out each individual character temporarily we're going to store it inside of a variable named C can be anything you don't this variable name can be anything you put whatever just don't put C har because that's going to cause confusion and then you type in this string that you want to cycle through or the collection like I said as the tutorial continues I'm going to show you how to cycle through other collections and then we could just come in here and we could print out each one of those individual characters inside of the string out on our screen and there you can see they are here are some random characters you can also see it puts out the spaces that are inside of there because the spaces are also considered characters okay so a whole bunch of things let's go and take a look at strings now one thing it's important to note is if you're creating a string and let's say you wanted to put a double quote inside of that string how is it going to know where the string ends well we have things called escape sequences if you wanted to put a single quote inside of there you just go and put a backslash and a single quote I'm going to put a double quote put a backslash and a double quote you want to put a backslash because we're using back slashes you have to put two backslashes just to get one if you wanted to go backwards back one space put a backslash and 8b and there's a newline and there's a tab there's a couple other ones but these are the ones you're going to use all of the time so let's go and create ourselves a string and do some different string operations let's go sample string is equal to and let's just a bunch of random words like that make sure you put semicolon at the end and we're going to be able to do all sorts of different operations on this we're going to print some stuff out on the screen we can check if the string is empty for example and this is something you'll do with if statements a lot so we'll say is empty and then we'll just go and get string we want to use the string class this is like a an object we're going to get more into objects and so forth as we go on this is just a nice handy tool we're going to be able to use and one of the functions it's going to be inside of here that we'll be able to use is is null or empty want to check both so we'll say through our sample string inside of there and then close that off this guy right here is going to allow us to be able to very easily figure out if our string is null or empty just says we could also let's just leave this is empty and we could say is null or let's say we wanted to check if it only contained whitespace well there you go just type in is null or whitespace and we'll say something like string length want to get the total number of characters inside of there in this situation we're going to go sample string like that and dot and length with uppercase letters and no brackets like that execute it you're going to say no it is an empty no it doesn't just contain whitespace and the total string length is 23 characters as you can see right there let's go and do a couple other different functions all bunch of functions for Strings let's say let's go console and let's say that we want to search for bunch the word right there so we could say something like index of bunch now each of these individual characters are going to be assigned indexes like a raise or hopefully you're aware of how arrays work and how indexes work basically this is the zero index this is the space here is the one index two three four five six and I messed up Bunch so what I want to do is I want to find out exactly where inside of this string the word bunch actually is stored and if it can't be found it's going to give me a value of negative one so you'll also be able to check that with your if statements if you want to find it you just type in index of pretty simple pretty much exactly what you would think it would be and then inside of here you're going to type in the word that you are specifically looking for and put that inside of quotes and of course inside of here instead of string we're going to put in the string that we are actually going to be searching for let's go into a couple more of these just so we can see them do another one let's say that you wanted to get a substring like you wanted to get we found bunch and we wanted to be able to pull bunch out of that string well we could do something like just a second word again we're going to be using sample string because that's what we're going to be searching through sample string and let's say that we wanted to start at the second character now first off we would type in substring a subpart of the total strength we want to start this guy here is going to say hey it said index - then you'll say ok fine I want to grab it I want to start at index two and reach the whole way out to index six and then I want to store that or print it in this situation and this is substring it's a little area and there you go if we execute that you're going to see right here index of word bunch is two and then we jumped in there and we grabbed the word bunch and pulled it out and print it out on a screen or we could just store it we could also let's create another string it's called as sample string two and we'll say something like more random words do some comparisons between these guys we could check if the strings are equal strings equal again simple string and to check equality this is very important say equals like that and then this will be sample string two that's how we check equality could also do string comparisons I just like to print these out on the screen that's reason why I'm using right line here we could check if a string starts awhile with the two words a bunch so you say something like starts with a bunch right like that and just to show you exactly how we would put in the double quotes we could do backslash n backslash and we could do Sam string this starts with pretty easy to remember these after you do it long enough and code completion helps a lot so we're going to check if that string starts off with the words a bunch right like that we could also likewise go and figure out if it ends with certain values so and with words words is what I'm going to be searching for in this situation and what again we'll say Sam string is what we're going to be searching for and I bet you can guess what I'm going to type here ends with like that and we could just submit and say words and if we execute you can come over here and you can see starts with the two words a bunch comes back is true ends with the words words you know ends with words and that also goes back as true and there we go you can also see strings are not equal right so a couple other different string operations we can perform here we could come in here and store restore value new value inside of sample string will also be able to come in here and go sample string and let's say we wanted to trim any white space for the string that is either at the beginning or the end you just do that with trim right like that you could also do a similar thing by just going trim and if you just wanted to get the white space off the end or trim start if you just wanted to get the white space off of the beginning and that's how trimming works we would also be able to come in here and replace words inside of the string let's say we want to store them in sample string just like we did before we would just go sample string and we could say replace and we could say what we wanted to replace which is words and instead replace it with characters that's how easy that is to do and I could print that out but I'm sure you know what that looks like could also remove starting at a defined index so we could say sample string equal to and get sample string and let's say we want to start removing at index 0 which is the first very first place up to index 2 doesn't take index 2 out so what we're going to be doing is just removing 0 1 so bunch is going to be the beginning of the string after we perform that remove operation right there and another thing we could do is we can create string arrays an array is just a whole bunch of strings all stored under one name in this situation it's going to be names arrays can store a whole bunch of different values like I said I'm sure if you're watching this you've seen other programming languages you know what an array is so let's say in this situation this is how you create an array by the way just type in whatever the data type is for all the values in the array 2 brackets right there then we're going to give it a name we're going to say new string and we're going to define exactly how many blocks we want to set aside and then we're going to inside of this store a whole bunch of different values so let's say neighbors I have or something like that there you go just created that we're then going to go into the console and show you how to join all of these into a string so we're going to convert this array to string array into a string all on its own so we can say list we're going to be using the string here and we're going to say join like that join the string array into one big giant just array then inside of this we have to define exactly how we want those to be separated so I want to calm in a space and then I'm going to find the array name that I want right there and there you can say aims and then we'll have name list and that prints out all of those difference guys right there on our screen another thing that's pretty important is what we would use for formatting basically I'm just going to show you a whole bunch so we'll say string this is call this format string it's equal to if you want to format a string you just go string format and let's define a whole bunch of things so I said if you want to transpose or move different values inside of here I'm going to use curly brackets and in this situation let's say that I want the data that's going inside of here to be a currency so it's going to have a dollar sign inside of it well pretty easy just go like this and then outside of that we're going to put a comma and 56 that's automatically going to convert it into a currency since I have the little 0 and the C inside of there we could also define decimal places with this value so it's like this in this situation we're going to say that we require well actually the 1 is going to define that I want the second value right here in the comma that's what that means some people get confused by that for some reason then what I'm going to do is I'm going to say I demand that there are at least two zeros and then two additional zeros for the decimal places that's going to handle decimal places for me here I'm going to throw in another one and let's just say that the value that I want to put inside of there in that situation is going to be 15 point five six seven so it's saying hey I demand there's at least two numbers inside of there and then two decimal places so what's that going to do it's going to chop off the seven and inside of here we could also define decimal places and if we put a hash symbol inside of here what that means is we don't care if you put a zero inside of there or not it's basically like I will you know whatever put a zero inside there or do not put a zero inside of there and that would work if we had a value that looked something like point five six so in that situation it's going to say well there's no zero here so we're not going to put a zero here but we demand that there's at least two decimal places so that's what that means and then we could also define that we want the thousand separator to come in here for our third or a fourth number in this situation and we would just say zero and then we put a comma and then another zero and close that out and whenever you see this it will all make sense and we could say a 1000 right like this and then we want to print this out on our screen and you can see exactly how it printed all those out in the thousands and let it out it Ida da da da there we go there's a whole bunch about strings now let's take a look at the string builder now each time you create a string you're actually creating another string in memory string builders on the other hand are used whenever you want to be able to edit a string without creating new ones and it's easy to make one you just go string builder and let's just call this SB and we're going to say new string builder that's what we're going to be visiting a stream builder object and then be getting more into objects in a second and if you want to be able to append another string to the end of your string builder you can use append line if you wanted to have a new line at the end of this but if you don't want a new line you could say this is the first sentence and then you could continue to append you could also do append format so pen format say my name is and then inside of curly brackets the first thing you want to put inside of there and I live in and then you can put the next thing you want to put inside of there and then you can put in whatever you want to transpose inside of there there's three different ways remember a pen line we put a new line after this if you do not put a pen line then it's not going to put a new line there you could also come in and if you decided you wanted to delete your string builder all the information inside of there just call clear and then you could also let's get rid of that you could also go and call replace if you want to replace every instance of the very first thing you type in with the second thing so let's say we want to replace the letter A and the letter e everywhere inside of our stringbuilder which is going to be a culmination of both of these strings that we created right here you could also remove characters starting in an index and then up to whatever you put inside there by going remove so let's say we want to start at index 5 and go up to but not including index 7 and then let's just output everything on the screen see exactly what it looks like and to do so you need to convert to the stringbuilder into a string so we go to string and execute it and you can see right there this is the first sentence my name remember we replaced all the A's with ease is Derek and indebted edit I and I live in Pennsylvania ok so there you go there's string builders in a rough overview of some of the things we can do with string builders now let's take a look at arrays now to declare an array remember you have to put the datatype of every single value inside of that array and then we're going to give it a value or a name or a variable name and that is how easy that is to set up that remember that is just declaring the array not going to be able to do anything with it if you also want to come in and declare an array and then also define how many items you want to put inside of it you're only going to be able to put the number of items inside of an array as you define here so here I have an integer array that I expect to have 5 values in it and no more than that and that's exactly how you have that set up you could also come in and declare and initialize an array all right like this no and then here whoops don't put new in that situation we're going to say 1 2 3 4 5 bottle of Allah and there you go and it's automatically going to set aside enough space to contain all of that data that you said you want inside of your array pretty easy to get your string length or your array length array length like that and say I want the second array right here just type in length and there you go that's going to get you the total number of items you have right there of course that would be good if you want to cycle through all of your different data also going to be able to come inside of here and let's say that we want to get item 0 inside of our array and just like the strings the first item inside of your array is going to be 0 index 1 2 3 & 4 if you want to go in there and grab the very first item inside of there you're going to go R and array 2 and then inside the brackets put the 0 and that's going to help put that on our screen if we want to cycle through our rice like I said before there's multiple different ways to do it let's just do this one like this we're going to start off with 0 because that's the very first item in the array I'm going to say as long as I is less than random array 2 dot length that's how length is useful length is useful in a couple ways though and then we can print out the information on our screen and we could also print out the index so let's say right line and then we want to put first item inside of there and then which is going to be our index and the next one's going to be the actual value that we have inside of there and then we could say I and then let's go and get the value out of our array right like this and then put the value of I inside of there because that's what's going to be incrementing as we're cycling through all this stuff and another way we could do this of course is with our for each block that we have again we're going to define the data type that we want num is going to be the temporary holding cell for each item in the array that we're cycling through random array is going to be what we're cycling through and then console right and then we could just put inside of here numb just to keep that nice and simple let's execute just see all the different things and you can see right here array length is 5 what is in the index of 0 1 you can see it's printing out all the different things and for each it's also printing out everything right there we could also come in here and say hey what's the index for a specific item inside of my array so for example we could say where is 1 so we'll search the entire array for the value of 1 and it's going to kick back the index and to be able to get our index for that guy we're going to use an array object index of and we're going to pass in the array name that we're going to be searching for and then the specific thing that we are searching for inside of that iraq like that and that's how easy that is but also here of course and create some string arrays and let's just call this names and I'm going to initialize it from the start so it's just put in some random names we could join an array into a string just like we did before let's go name string is equal to and then we're going to call string join we're going to say what do we want between each of those strings what we want to call them in a space and then the actual array that we're going to be working with and it's going to automatically join those together and save them into a string we could also come in and split a string then into an array so string there's a string array call this name array is equal to and name string and then call split on that and then inside of it we're just going to put what separates all those names in the strings which is going to be a comma and execute that see where is one it's in the zero index and the other stuff then we'll actually do anything but if you print this out you'll see exactly how those work and why don't we just come in here and just create a multi-dimensional array just so we can cover all that so let's say we wanted to create an integer multi-dimensional array let's just say it's going to be a two-dimensional right we're going to not put anything inside of there but we are going to put a comma mult array is equal to new and it's going to be an integer multiple array or multi-dimensional array and let's say we want it to be 5 by 3 that's exactly how we would define that we could also of course come in and do pretty much the same exact thing and initialize the multi-dimensional array at the same exact time so multi array 2 is equal to this is sometimes easier because it's easier to see how everything is going inside here so there we go and this is how we would separate each individual part of our multi-dimensional Rex a 2 & 3 you see there's another column inside of there and then inside this one we'll put 4 & 5 and then finally to close that off we've just put our semicolon inside of there we could then cycle through our multi-dimensional write in a couple different ways we could either use for each like this again the data type num in multi our I to that guy right there and then we could on our screen just each one of those individual noms which is where those going to be stored or sometimes we also want to be able to print it out in different ways so let's say we want to cycle and have access to all of the different arrays we could also go int X is equal to when we're starting off zero index X is less n and we could say multi ray to going to get the length of it we could go get linked and throw in zero inside of there that's going to give us that and then we could say X plus plus if you were wondering you could also go X plus equals to one right like that but let's just just trying to cover everything as I'm going through here as things pop into my head okay so that's going to give us the first part of our array but we want to get the second part of our array as well so we're going to go int and let's say Y is equal to zero and we're going to cycle through this as long as Y is less than the multi array two and again we're going to go get length like this and in this situation I'm going to put one inside of there then we're going to increment the value of y as well and now we can access everything so we could go console.writeline and we'll throw in the first part we're going to put inside of here throw like a or same inside of there and we're going to get another value inside of that and then the final actual value that is stored inside of it right like this now what we can do is come in here and grab x and y and then to actually get the value that is stored in our multi-dimensional array there you go Balto array two and then throw in x and y at the same time and we could save that and execute it and you're going to say it prints out our multi-dimensional array which is sorts often 0 0 index and this is the value and so forth and so on so there is a heck of a lot about a race let's go and take a look at lists now a list is like an array however unlike an array whenever you add new items to a list the list is going to automatically resize for you and how we're going to create a list as we're just going to type lists and then the type of data it's going to contain create a number list and then you just go new list and then the data type that you want to and the brackets for the function now to add items to our list we just type in ad and you can just throw in as many different items as you'd like to and there you go and you don't have to worry about the size of your list other things kind of neat is it's very easy to add an array to your list so let's just create an array here and there it is now you can just go num list and of course the data type has to be the same so make sure that you do that and then you're just going to go add range instead and then make sure you put a little dot inside of there there we are and then inside of here you just put in the name of the array that you want to put inside of there pretty simple you can clear your list by just going on list and then clear like that but why would you want to do that can also copy an array into a list so I'll just create a list let's go to number list to new list and the data type you want inside of there and then in this situation you pass in the array that you want to put inside of there and you could also create a list with an array in a very similar way so let's list three equal to new lists and then inside of it we'll just define our array inside of here so it's an integer array and then we could just put 1 2 3 & 4 or whatever you want inside of there let's say you wanted to insert an item into a specific index let's just go nom list say insert and you're going to say first off the index you want to insert it into so the one index number it starts at 0 and there we go we just inserted that we could then remove an item specific to its name so remove 5 you could remove added index so remove a specific index with remove at and then of course you could cycle through your list just jump it in here and just like you would with an array and you can also see here if you want to get the length of your list you use the count function right there if you execute you can see all of those lists items print out right there also be able to come in here and return the index for a specific value pretty easily so say something like 4 is in index and we're just assuming that four is inside or here and we could say number list let's just change this to three just use a different one and then we'll say index of like that and then the specific value that you're looking for right there and it's going to return negative one if it doesn't find anything likewise you could come in and check to see if an item is inside of a list so we could just come in here again and we could say something like five in list we'll just go number list again and contains and then the item that we're looking for specifically inside of there and you could also search for a value in a string list so let's create a string list same exact thing like this new and we'll go and create a new string array right inside of here and we could just put in some names and then close that off and then we could say something like Tom in list and then we'll use the string list here instead so string list and you're going to do pretty much the same thing contains another thing that's useful is we could actually use lowercase letters here however if you do that you're going to want to go string compare that guy right there and then ordinal ignore case right there so what we're going to be able to do is search for Tom and even though this is a lowercase T it's going to be able to match that right there and you want to close that off then the final thing we could do also is if we wanted to sort our list we could go string list and sort and it's going to automatically go in and sort that alphabetically or numerically depending upon the type of list items you have all right a whole bunch of stuff let's go and take a look at exception handling next now there are countless numbers of different exceptions I'm just going to focus in on exactly how exception handling works inside of c-sharp here and on on my website or in the link in the description you're going to find a link to all of the different exceptions I'm going to do a / 0 exception right here and we use exception handling anytime we want to keep errors from going out to the user of our software so let's go in is equal to int and if we want to convert from a string into an integer we use parse or int dot parse or double dot parse or whatever how we can do our conversions because we want to convert the read line which is a string into an integer and then we can print some stuff out here on the screen something like 10 divided by and then we'll throw in whatever they put inside of there is equal to and then we'll throw in our final result and then we'll just put in num and then we'll put in 10 divided by num that's the second thing that's going to show up there on our screen all right so inside the try block we have what we think is going to maybe lead to an error which is division by zero error now what we have to do is catch an error and we do that with catch like you probably would have guessed and this one's called divide by zero exception and I'm going to put e^x inside of there so I can get additional information about that exception console right and we could just do something like we can define now exactly the error that the user is going to see so that they don't just get a whole bunch of junk all over their screen so we're going to say can't divide by zero custom error that we or a custom message that we will show them if there's an error now with the e^x we're going to be able to come in here and get additional information on the exception so two different things we can get we just go e^x and then we say get type and then we can say name and that's going to get us the name of the exception that was triggered and then we could also come in and get an error message that describes the exception just like that another thing we could do is go throw e^x which is going to throw the exception for another part on another catch block to be able to handle and another thing you could do is throw a specific like let's say we catch an exception here and we want to throw another exception we could go throw new and in valid operation exception just whatever that is you know just to throw something out there and then we could also put a message inside of here operation failed and also along with that throw the exception information inside of there so we'll be able to handle that put the semicolon on the outside of course and then finally we also would have our default option for caching every exception that isn't caught anywhere else and that's just catch exception with the generic exception port there and then we could put all types of error messages we could just come in here and grab this right now and throw that in there so there's the basics of exception handling just one to cover exactly how that operates and now I think it's definitely time for us to talk about classes and objects all right so I'm guessing you guys know the difference between a class and an object basically a class is just a blueprint we're going to need to use to define the attributes and capabilities of the objects we're trying to model okay so let's just come in here and create I'm going to change the class name here to animal and I'm going to come in here and define some properties for this guy now there's going to be different ways we can limit access to the different properties we have we're going to have public which means that access is basically not limited protected is going to say that access is limited to specific class methods so the methods inside of our class however it's also going to be accessible to subclass methods that we create later on and private is going to say basically that access is limited only to this specific classes methods so we're just going to keep this simple and create some public fields or attributes or whatever you want to call them and see short provides a really easy way for us to set getters and setters we just do that it automatically generates them so we're going to have our animal it's going to have a height and we're going to be able to set those using getters and setters methods and we'll also have weight and you're going to see what those look like here in a second also for each animal that I'm going to create it's going to have a string and it's going to have a name or why don't we go and have this beast sound specific sound it's going to create then I'll show you how to also come in and create your own getters and setters if you'd like to do that and let's say we have string like that and then name and since we're going to create our own getters and setters we'll get rid of that well now what we're going to be able to do is go public string and I'm going to make this an uppercase name unlike that and then inside of this create the getters and setters and the get that I want to use here is return name and the setter that I want to have here is name is equal to value you may say to yourself well why would you want to do that values very important value always has to be used because that's the default for setting any of these different items in c-sharp so make sure you use that this you can have it be anything but and in regards to why are we using getters or setters basically with the getters and setters we're going to be able to either limit access with the get port or only allow them to set certain values with the set part so for example we could come in here and maybe check to make sure that the name that they want to set for our name property doesn't contain numbers if it does we send an error message it says hey you need to give me another name it doesn't have numbers in it otherwise I'm not going to allow you to set the name and so forth and so on I figure you got the handle on that what we're going to need also now that we have some attributes for our animal object is we're going to need a way to initialize these new animal objects and to do that you're going to use a constructor now the default constructor is automatically going to be created for you unless you create one on your own then it's not going to be created how you would create a default constructor that doesn't receive any attributes is like this then what you're going to be able to do is come in here and set values now whenever you create an animal object later on you're not going to have any way of knowing what the name is so if you want to refer to attributes for any type of animal object you use this followed by the attribute you want to set and in this situation I'm just going to set a whole bunch of default values for every animal object that's created that isn't passed attributes you're going to see here in a second what it looks like whenever attributes are passed in now we're going to define the weight and we're also going to come in here and this is also how you set values with a dot operator like that and then what's also set a sound and of course we're going to have to have the name I'm going to put no name inside of there just so you can see very easily that there's no name assigned and no sound and then let's say that we also want to come in here and maybe track the number of total animal objects have created well how could we do that well and one thing to think about is this is going to bring us to the concept of statics well before I get into that let me jump in here and just show you how to create the other constructor that's going to set our variables for us or our attributes again you're going to go public whatever the class name is and then you're going to find the data types for everything that's coming inside or here and sound and then you're basically going to do exactly the same thing we did here we're just going to go this animal is going to have these values assigns to its specific attributes so in this situation we'll say height and here we'll say weight and then here we'll say whatever the name is they passed inside of it and then this is going to be whatever the sound is they passed inside of it so you can see here where it makes a lot of sense that these animals would have Heights and weights and names and sounds okay however I also want to be able to track the total number of different animal objects have created now does it make sense for an animal to be able to track or count the number of animal objects created now in situations in which you get that answer whenever you want to add a capability but it doesn't make sense for the object to have that capability that is whenever you're going to use what are called static fields now static field is going to have a value it's going to be shared by every object of the animal class in this situation and like I said we're going to call something static when it doesn't make sense for the actual object to be able to perform a certain operation so a static field attribute is starts off a static data type num of animals okay so that's what you want to store inside of here and like I said this values going to be shared by every animal object ever created ever now you may also want to be able to get access to this static value so we're also going to create inside of here a static method and we're going to make it public so anybody can get ahold of it not just class methods it's going to return an integer and get of animals no attributes going to be passed inside of this function it's just going to return on all the animals whatever it's called and another thing we can do here is each time one of these constructors is called we're going to be able to come in and go numb all animals right like this paste this inside air and increment that and then do the same exact thing here paste that in there and increment that and there you go now we have some attributes for our animals as well as the Constructors and the ability to go in and increase the number of animals that we have total let's go in here and create a couple other different methods for our animals to be able to operate with we'll go public this guy right here is going to just print out a bunch of information about all of the animal objects and this is how we define our methods so we'll say return string another thing it's very important to understand is a static method is not going to be able to access non-static class members so this guy right here isn't going to be able to access these attribute values up here it's going to only be able to get this because it is static put that in back your mind so this guy right here is going to return a string so I'm going to say string and I'm going to format this guy and I'm going to get all the individual pieces of information about my different animals this is going to be the name of my animal and it's so many inches tall weighs and I'm going to get the amount that it weighs pounds and likes to say and then whatever its sound is if I want to get access to those things I just go name height weight and sound it's automatically going to know what animal I'm specifically talking about so I'm going to jump down in the main section and actually create an animal object pretty easy to do just go animal and I'm going to tall my animal spot equal to new animal and let's just say 1510 name is spot as well as wolf is his sound that he makes there you go just created a brand new animal object and it's called this constructor that we created up above now you can come in here and actually get the different items for our animal print them out here on our screen and we're just going to do it just like we would normally do it says and that if we wanted to get our specific animal object named spots name we just put spot dot operator name and if we want to get his sound they just go like that if we want to call the static method that we created previously let's go and copy this paste that there you could say number of animals and to call the static method you're going to type in the class name followed by get numb of animals its name and that's how that works so you don't use spot you need the class name before that because that static method belongs to the class it doesn't belong to the objects and we could also come in here and call the objects method by going spot and then to string is the name of that guy and we don't put it inside of quotes and that's going to output all that information about our animals and you can see right here spot says wolf number of animals created as one spot is 15 inches tall weighs 10 pounds and likes this a wolf okay so there we go pretty simple example but an overview of a lot of things so I showed you how to create an object method right here with two strings let's say that we wanted to also explore something called method overloading what this is going to allow us to do is actually work with different attribute types but also use this same method name so let me just show you so let's say we want to let's say we have a really smart animal that can perform addition I'm going to create a new method inside of here a function whatever you want to call it called get some and it's going to get an int and it's going to be called number one if you want to give a default value to assign if no value was assigned you would just type in this like this is equal to like that all right so that's going to create a default value of one if nothing is assigned then what this guy is going to do is return I'm 1 plus num2 right like that pretty simple function but we can also what the overloading part means is as long as we have different attributes data types we're going to also be able to accept doubles and then also return doubles but you have to have different attributes inside of here but we're just going to go double this this is fine if you just had double an int that would work but in this situation I'll just do two doubles like that and now what I did was I set it up so that we'll be able to call get some and pass in two integers or get some and pass in two doubles it's still going to work called method overloading and to see exactly how that works we could just come in here like that and then go to spot dot get some like this and then pass in a 1 and a 2 and know that that's going to work but also come in and pass in one point four two point seven and also know that that's going to work another thing that might come of use is you could also come in here and pass in these attributes in the in correct order what we have to do in that situation is go and say which do we want to assign to so this accepts num1 and num2 we could go like this and num1 and then a colon like that and that's going to work perfectly well you can also create objects using what is called the object initializer so let's say we want to create another animal called grover just go new animal like that and then come in and assign all these values individually so equals to grover and it's sound is equal to and it could put goro or something like that and then all you have to do is at the very end of this put a semicolon there's another way to create objects and see short and another thing we could do is we can create a subclass of animal and that subclass is going to get all of the attributes that are defined and methods that are defined in our animal class and we'll call this one dog so we want to come out of this guy all together we don't want to be in this class at all being the same namespace that's perfectly fine so down inside of here if we want to create a class that is going to inherit all the attributes and methods in the animal class we just put the colon erin animal there we go it's pretty simple we could also come in and of course add in our own new attributes that only dogs are going to have and we could say get in set that's automatically going to generate all that for us we could also go and create a custom constructor that's going to set favorite food and we go public dog name of the class right there and if we want to also be able to call the superclass we would go : and base that's going to allow all the initializations that's in the superclass constructor all this stuff is still going to be taking place so that's really useful because then we'll just have to come in and go this book favorite food like that is equal to and then the default is going to be no favorite and then this because this guy right here is there it's going to initialize all the other different parts to exactly what was assigned in the animal constructor so that's pretty useful this guy right here it's going to call the default one right there we're also going to be able to come in and create a more elaborate constructor that's going to set values that are passed inside by going dog and we're going to find all the different things are going to be passed aside so we have our height and our way and our favorite food and make sure that the string is defined inside of there there we go so this constructor is going to accept everything that's in the first one and also get favorite food now if we want all of this to be passed into the constructor in the animal we just go base and then pass in height weight name and sound and it'll take care of initializing all of those different guys so that means all I need to do is come down here and go this favorite food right like that is equal to the favorite food that they passed inside of it so that's useful we're also going to be able to override methods in animal inside of our dog class so let's say we want to override to string well we just come up here and copy some of this stuff because it'll be useful that and paste that in there so here we have new string or two string and we want to override it we want to override a method we type in new and there we are now we're overriding it we can leave pretty much everything else like this and then we could just say something like and eats and then throw in another thing for the favorite food for our animal and then go favorite food and it's automatically going to update that and if we would come in and execute all this stuff let's go and create a dog inside of here just show the differences go create dog let's call him spike new dog create that just a generic old dog and then if we want to come in and call the to string on that just to show that the to string is going to work and we'll be able to to call and set off everything initialize everything using the base class of animal do that and we could also overwrite that by going spiked new dog and then pass in some information about our dog so 15 spike and ger whatever and then finally let's say that he likes chicken or something there we go and we created spike in two different ways and we could go and call to string again print that out and if we execute it you're going to see here is where we created spike with no name and there's all that information here spike with all of the information and you can also see each chickens on there there you go guys that is how we create or use inheritance where we inherited every attribute and method inside the animal class into work dog class another thing that's interesting is we're going to be able to implement what is called polymorphism through the use of an abstract class we could also do the same with an interface but let's go and show you exactly what an abstract class and interface look like so let's come down here after dog is all closed out very much at the end basically an abstract class is just going to define methods that must be defined by those classes that derive from it one thing to remember is you're only going to be able to inherit one abstract class per class however with an interface you'd be able to inherit multiple interfaces another thing it's important to remember is you can't instantiate or create an object out of an abstract class so let's come in here and let's create an abstract class like this and its name is shape now we're just going to define kind of like what this method is going to look like it's public abstract it's going to return a double and it is going to be called area so we're going to be able to create different area calculations depending upon the type of shape we're using another thing it's important to know is an abstract class can actually contain methods that do things or non-abstract class so we could say something like public void say hi something completely silly but whatever and then we could say console.writeline and then it's just going to print out hello on the screen can't do that with interface interfaces only can contain abstract classes or methods like that I mean so only abstract methods inside interfaces but an class can actually contain real methods that do other things and we come down here and go and create into your face just so you know what it looks like so let's create interface public interface and let's call this shape item just to have it be something different and every single method inside of an interface is an abstract method so you don't need to put the abstract part inside of there all you need to do is go double area like that and there you go you have an interface and it's going to say that anyone it wants to inherit this interface must have a method inside of it called area seems true up here with shape however of course it's not going to require that you have a se Aiye method only if it has abstract like that now what all this means is we're going to be able to come in here and create a new class and let's call it rectangle and we want to inherit from the shape abstract class well that's how hard that was now you have the requirement to come in here and use the area it's actually going to give you an error saying hey you need to do some stuff and you need to put the shape area edit edit ah you click on show potential fixes and click on implement class and they're dead it automatically threw it in there now what I can do inside of my rectangle class that I have right here is go private double and a link like that and then private double width then come into the area part right here and say it's going to receive a double number one and another double number two and then it's going to assign those values to link but is equal to num 1 and width is equal to num - there we go well actually this isn't the right one Stu that with let's just come in here and just get in you clicking around doing so many different things what we're gonna do is this is going to be the constructor sorry about that I'm sure it didn't confuse you and then we'll put the double inside of here like this let's just get rid of that area is not going to receive anything there we go now we got that inside of there now we'll be able to come in here and put the length and number one inside of there there you go that's the constructor you'll call when you create rectangle objects and then the area method that we have inside of here what it's going to do overwrite any time you want to override a method must put override inside of there and then we'll say return length times width and there we go now we have a rectangle that's going to calculate area for us but the reason we want to set this up right here is we want to also be able to calculate using other different types of shapes another different type of shape we're going to work with here is a triangle it's coffee a lot of that so I'm going to change the name from rectangle to triangle still going to be a shape it's going to instead receive a base I can't use the word base because that's a key word and C sharp so I'm going to just type in the base and here I'm going to type in height and this is going to be triangle this is the constructor again it's going to receive two numbers just like before the only difference is in this situation it's going to say the base like this and then this guy right here is going to say the height and then I'm going to be able to come down inside of here and leave area remember it has to use area I'm just going to calculate area in a little bit different way we're going to go point five times and then we'll go to the base like that times height and you can see that we have two different shape classes here that are going to allow us to calculate area in different ways well I'm here in rectangle when we talk about operator overloading kind of cool basically if we wanted to be able to figure out ways to use a operator of addition to add rectangles together could we do that yes we could so how you do it's practically pretty easy we're going to go public this is going to be a static method it's going to return a rectangle and if you want to overload an operator ego operator and then you follow that with whatever operator went over lit so there's a plus that's when I want to overload and what this is going to be to do is it's going to receive rectangle let's just call it wrecked one and another rectangle will call it wrecked two and it's going to define exactly how these two guys are going to add together so we're going to say double and I can get my rect length for my new wreck tangle I'm creating right here by going rekt one and getting its length plus wreck two and getting its length there's a brand new length for my brand new rectangle that's going to be used whenever I want to add rectangle objects together which is really neat and then this one's going to be the wit like that and here I just change this to width instead and change this the width and then what I can do is just return a brand new rectangle object using the combined length and width or whatever you'd want to do so that's operator overloading inside of c-sharp with the addition but you also do this with pretty much every other operator that you can think of really neat so now let's jump back up here into our main class and play around with these different guys we can get rid of all this and now I'm going to show you how to implement polymorphism through the use of an abstract class so I'm going to create a shape call it rectangle is equal to new rectangle five five let's give it that value right there or pass in those two attributes and then I'm going to create another one also a shape but this is going to be a triangle and we'll just call this tri like that and here see these are both shapes even though this one's a rectangle and this one's going to be a triangle like that and what's neat is this is polymorphism it's automatically going to call the right area method depending upon this even though these are both shapes and you'd be able to throw these guys into shape arrays and do anything you want because remember array can only accept one data type to get through a whole bunch of shapes in there but they're actually rectangles and triangles and it's automatically going to calculate the proper area so let's go and look at it so we go area like this and to calculate that just go rect and area call the area method write that now we're going to do the same thing for our triangle this and this will just be try and then we'll just try inside of here as well and why don't we take a look at overloading so we'll go rectangle where we overloaded the plus sign so we'll create a new rectangle let's just go and throw a new inside here like that and pass in five and five like that and then we'll add it to another rectangle and throw five and five in there like that so we're using this guy that we overloaded so we'll be able to add two rectangles together to create a new rectangle and then we'd be able to come in here and console right and say something like combined rectangle area is going to be equal to and we'll be able to come in and go combined rect like that it's going to work so cool and you can see right here the area for the rectangle is 25 the area for the triangle is 12.5 and the combined rectangles have an area of 100 so so many different things covered hopefully they all made sense and of course leave any questions you have below I answer every question I get and I want to talk about generics and generic class in general basically why generics are really cool is with the generic you don't have to specify the data type of an element in a class or in a method it's going to automatically work let me just show you how they work make a lot more sense whenever you just see one let's create a class and let's call it key value and it's a generic so I do not know what the data type for the key or the value are going to be T value like this and then inside of it I'm going to go public Tiki give it the name of key it's going to have getters and setters but I don't know the datatype for either one of them public create another one this is going to be T value this so it's going to contain each object of type key value is going to have a key and value all right so we have that all set up and we don't know what their data type is if you want to create a new one you just go key value call the constructor just like anything else TK give it K and then T V once again finding these bizarre datatypes we're not giving real data types here but they will get real here in a second and then we could say something like ki is equal to K and then value is equal to V see we've gone quite some time here and we still don't know the data type we're dealing with that's because we can deal with pretty much any data type we could then go public and show data for our method and then here we could throw out some information on our items we could say something like 0 is 1 and then we could grab the key by going this key and this value that's going to shoot that out on the screen and that's enough information you of course know how to go and create methods and do additional things here so let's go back up inside of main right here with this guy and let's create a new key value class object and here is where we're going to define what we're passing inside so we're going to say hey we're passing in a string to strings actually one for the key one for the value and we'll call this key value object Superman and say new and then we'll go key value and then we'll pass in string and string I have to have the same thing there we could pass in nothing in regards to values like that and there you go and then we could also go in and go Superman key is equal to and have the key for Superman be the word Superman and Superman dot value be equal to Clark Kent and that is how easy it would be to create that and we could also create ones with two different other data types or any type of data type so it's create another one and this one we'll call it Samsung TV like this and instead of having a string here we could have this be an integer and then this could be an integer we could change them both to integers I don't need them need to be strings we then have to assign value of zero to that guy right there and then Samsung TV and we'd have to assign a key for it but this is an integer in this situation so 1 2 3 4 5 whatever it doesn't matter Samsung TV and the value for that and we could say something like a 50 inch Samsung TV to describe that and then we could come in and get Superman and call our show data method like that and then do the same thing for Samsung TV dot show data like that and execute it and I had a little bit of an error here go down here put a calm inside of there and we'll execute that and you can see that it automatically went put Superman's Clark Kent in there as well as handled the TV port so that is how you use generic classes okay so now let's talk about enumerated types now basically an enumerated type or an enum is a unique type that's going to have symbolic names and then associated values and we're going to create these guys outside of our class so we're going to throw them right here and to create one we just go public you know them and say we want to do something with temperature making a microwave that freezes and boils and does a whole bunch other things I don't know first thing came to mind so here it's going to freeze it's going to have a setting of low and it's going to a setting of warm and it's going to have a setting all boil okay so there is our numerator type we just created right there we could save that we could also come in to this is going to get the default value of zero one two and three if we wanted to give us a different value we come in and have the D value stored at one instead if you'd like to do that but I'm going to keep it this way so we save that enum called temperature now down inside of main what I'm going to be able to do is go and call temperature which is the data type I just created right there and let's call this Mike temp like that and I'll be able to set the temperature for it by calling temperature and then followed by low just that easily and I went ahead and threw in a switch statement here that's going to check the value of right here and then you know print out different output depending upon whatever the value is set for I'm gonna execute that and you can see right here it automatically prints out temperature is low and I could also come in here and change this to warm and it's going to also work that way that that a temperature is warm so that's how enum work inside of c-sharp now let's take a look at Struck's now a struct is a custom type that's going to hold data for many different data types and on top of that it can also have methods inside of it to offer on that so we can create a struct again outside of our class and let's say we have a struct called customers there we go and I could just go and put some customer information inside of here private let's say we want to have a balance if the customer maybe owes us money and then also an ID number for our customer okay so there's all those different attributes all of different data types doesn't matter we could then provide a way for us to create a customer so it would receive a string and a double for our balance and another integer for our ID for our customer and then if we want to assign the values we would just do it this way pretty simple there we go so that's a way to create our customers when inside of this struct we could do all sorts of different things with this customer information but this situation we're just going to display information about the customer and in this situation we'll just do just some information we'll just print it out on the screen and to do so just good name and to get the name for this struct just like that and then we could do exactly the same thing for the balance as well as the ID exactly like that so there we go the name balance and ID so we're able to create customer store customers print customers and all those other different things go down create a customer to create a new customer we just go customers or its customers is what I called this struct up here I believe yes customers so we'll go customers and we'll have a customer named Bob and to create a new one very much like you would create an object that's how it's set up and then we could go Bob create the customer call that method to create him passing Bob 15 let's say he is is fifteen dollars and 15 cents and he has an ID of that and then we could go Bob dot and then show customer like this and there we go and it prints out all the information about that struct or that customer so that's how structs work inside a c-sharp covered a lot of stuff here no suck about delegates now a delegate is going to be used to pass methods as arguments to other methods and a delegate can represent a method with similar return types as well as a similar attribute list and once again something that's probably better to see so let's go delegate this is how you create one double and we'll call this get some and it's gonna receive a double and another double there we go and we're defining this outside of our class and now what we're going to do is we're going to use this inside of an anonymous method and let's come down here and there's lambda expressions regular anonymous let's just talking about an anonymous method basically an anonymous method has no name and its return type is defined by the return that's actually used in the method so we're going to use this delegate here get some and we'll give ours the value of sum equal to delegate and then you're just going to define inside of this the number one and the number two double number two and there we go and this is an anonymous method it doesn't technically have a name so we can just go num1 and num2 right like this and then if we would come out of here make sure you put a semicolon right there we could then come out and print to the screen right line and we'd also be able to pass this in as a method operator or a method attribute with but just by passing in some using get some as the data type that we're passing into a method then we can just go five plus 10 is equal to right like this and then call this anonymous method by going some five and ten like that and then of course make sure that we wrap this inside of our main function like this file save it execute and you're going to say 5 plus 10 is equal to 15 drops up there on our screen so that's how you use an anonymous method now let's look at lambda expressions which are kind of similar now basically a lambda expression is used to act as an anonymous function or an expression tree now you're going to be able to assign the lambda expression to a function instance like this so we go function go int this is just going to work with 2-inch here and we could say something like we give us a get some like that to sign the value to get some and the way these guys work is you pass in the @ buttes on the left side of the screen so we're going to give those the value of x and y you're going to put this a little equal sign looks like an arrow on the right side and then inside of here you're going to be able to perform all of your different statements that you want to happen inside of there you can see and this is a lambda expression now what we can do all in this one place make these calculations we can do write line and then 5 plus 3 is equal to and then call get some invoke and then pass in five and three which is going to go into that expression right there and print that out on our screen for us oh yeah 5 plus 3 is equal to 8 right there another thing that is a little bit even more cool with lambda expressions they're very often used with lists so let's say we have a list and integer lists like this call it number list equal to new list throw some values inside here 5 10 and 25 one heck there we go so we create our list now we're going to be able to use this lambda expression on every single item in this list like I said before and we're going to be able to store it in a new list so we'll go create another list and this is going to be called odd gnomes equal to num list list that we created a second ago we're going to be able to say where this comes from something called link I could do tutorials forever and I'm probably going to do a longer c-sharp tutorial here soon because there's just so much about Seashore so what we're going to do here is we're going to check to see if any of these guys are ODS and if they are we're going to store them in odd numbers like this they do is you go like this and you check that this is equal to one if it is then we want to convert it to a list and then we want to store it over in odd numbers right there so we just in this one line we went and cycle through all the items in the list checked if any of our odd numbers if they were then we stored them in this guy and then we'll throw up a for each block like this no we could cycle through all the different items inside of that list right like that and print them out on our screen and there you can say 5 15 and 25 printed out on the screen then the final thing to talk about is file i/o and I'm starting to lose my voice so what I'm going to do here is just explain exactly what's going on basically we're going to be able to use things called stream readers and stream writers to will allow us to create text files and then either read or write data to them now there's a whole bunch of different ways of working with file i/o inside of c-sharp this is just ways of saving text data so I'm going to do here it's going to say there's an error here show potential fixes and that means I need to include a library and there we are now that all fixed so I'm going to do now is I have a string array called customers if I want to be able to write to this I'm going to use the stream writer to create a brand new text file called customers dot text right like that or cost X I'm then going to be able to cycle through all of the different customer names inside of that temporarily store it inside of here and then if I want to write it to the file I just go and go stream writer and follow that with write line and write each individual word inside of there and then if I wanted to read that information out of my text file I need a stream reader which I called s or I have to define exactly where I want to read it from and then once again I'm going to cycle through all the different lines of text inside of that text file and output them on our screen and there you go guys that is how we do so many different things inside of c-sharp I wouldn't did a couple more of them I throat is really rough and messed up please leave your questions and comments below otherwise till next time

Channel: Derek Banas

Views: 1,416,191

Keywords: C# Tutorial, C# (Programming Language), C# Programming, Learn C#, Programming Language (Software Genre)

Id: lisiwUZJXqQ

Length: 84min 58sec (5098 seconds)

Published: Sun Jul 05 2015

Reddit Comments

[u/AngularBeginner]

Why don't you follow any common convention? Especially when trying to teach someone you should stick to it.