ArrayList in Java Tutorial

you may have heard of a rayless and it's like we have a raise why why do we need something else but in this video I'm gonna show you exactly what arraylists are how they differ from a raise and how you can use them to make your life easier what is up my name's Alex welcome back again to another Java video on this channel I hope you learn java by posting a new java tutorial every week so if you're new here consider subscribing let's get this party started by going to file new Java project we'll call it something like arraylists project finish open it up click on source go to new class and we'll call it array lists project again hit this first check mark and hit finish so I'll just go over arrays again say we want to have an array of fruits which are strings this is how you make an array and we need to know the amount of items in it to add an element into our fruit so you want to add a mango mango now we'll add the rest if we print these to the screen will say fruits 1 save it and run it we'll see the apple now here's how you do this exact same thing into an array list instead of an array we would type array list and we'll name it a fruit list and finish it off by typing this code right here hover over array list this lets Java know hey we want to import ArrayList into a program that just means we're gonna be using it add fruits into our fruit list we just typed the name fruit list and then do a dot this brings up all the things that this ArrayList can do you don't need to know all of them but today we're gonna be looking at this add 1 so click add hey we'll put our mango in there finish it off by adding our other two fruits fruit list add Apple fruit list dot add oops strawberry no print out all of the fruits by doing systems that out the print line fruitless like that will save it and run it we see the Apple from the fruits array and then we see all three elements from the ArrayList if we tried to print out elements from the array like this fruits and tried that it would print out this gibberish so the ArrayList is more flexible because we can see all the elements by printing them out but arrays are a little more work here's another difference if you want to add another fruit let's say let's add a watermelon to an ArrayList we do fruitless dot add watermelon save and run that it's automatically added that was super easy but for an array a regular array we would have to create a third index and put watermelon in here save it let's see what happens we get an error because we actually have to change the size so with an array you have to know the exact size every time but array lists are flexible they don't care they can grow and shrink whenever you want this is useful for things like YouTube subscriptions people are subscribing and unsubscribing to channels all the time so that list grows and shrinks every day it would be super annoying to have to recreate your array so they just use an ArrayList probably or something like an ArrayList some other neat things you can do I'm just gonna save and run this again no errors this time we can remove elements from an array list by typing it doing a dot and then scrolling down to the one that says remove and click remove say we want to remove strawberry we can do that really easily save and run that no strawberries gone you can remove all the elements from an ArrayList by doing fruitless clear save and run and now it's empty you can really do all sorts of things with it I'm just gonna try one more thing we'll see oh okay we can see if our free list contains something so we'll see if like there's a raspberry in there which there's not and we'll print out the results of that because this will give us true or false I'll comment this out for now since we don't want to clear it save and run see what happens false it's because our fruit list does not contain raspberry so none of this cool functionality is available to you with a race you would have to code it yourself so we use array lists because they're more flexible you can add remove clear see if it contains what you're looking for and it raised a really bare bone they're better for smaller things if you know their exact size likes on videos and comments always make me happy because it means I'm helping you and these videos are helpful for you but for now I'll talk to you later you could be anywhere in the world but you're here with me and I appreciate that so much thanks see you next week bye [Music]

Channel: Alex Lee

Views: 210,364

Rating: 4.9690247 out of 5

Keywords: arraylist in java, arraylists java, arraylist java, java arraylist tutorial, java araylist, arraylist java tutorial, arraylist in java for beginners, array list, arraylist in java with examples, arraylist in java example, arraylist, arraylist java example, java arraylist class, arraylist methods, dynamic array, java (programming language), kk javatutorials, java interview questions, java interview questions and answers, core java interview questions, java basics, edureka

Id: pTAda7qU4LY

Length: 5min 50sec (350 seconds)

Published: Thu Jan 31 2019