Return Methods

Quick reference

• 00:04 Okay, in the last video I showed you how to pass parameters into a method and
• 00:07 then do something in that method.
• 00:09 But many times you're going to want to pass something into a method,
• 00:12 do something, and then have that method return something back to your main program
• 00:17 and then do something, all right?
• 00:19 So that's what we're going to look at in this video, returning methods.
• 00:22 So here, we're passing a 4 and a 1 and then we're writing everything out here.
• 00:29 Well, we might not want to do that.
• 00:30 Maybe we just want to do the math in this function, right?
• 00:37 X + y.
• 00:38 And then return whatever the answer is back into this main method and
• 00:43 then here console write out the answer.
• 00:46 So here it goes console.write line.
• 00:50 And then we could again do this guy,
• 00:55 we could say a + b = result, all right?
• 01:01 And we need to change this back to a and b.
• 01:05 So in order to return something from a method,
• 01:07 we need to change the definition of the method, this thing right here.
• 01:10 So up until now we've been using void.
• 01:13 Again, our main is void, but when you want to return something with a method,
• 01:17 you need to use a data type.
• 01:19 So in this case, we're going to be adding x + y and returning an integer.
• 01:23 So instead of void, we need to change this to int, right?
• 01:26 So we're going to return an int, so this is now an int method, right?
• 01:30 So inside of here, if we want to return something, we just type in return and
• 01:35 then do the thing, right?
• 01:37 So this will return x and y, which is this and this,
• 01:41 which are a and b when we ran this guy, all right?
• 01:46 Which are these two things.
• 01:48 So here we can do this several different ways.
• 01:50 We could just call it like this inside of here.
• 01:54 That will work and we need our semicolon there.
• 01:57 So if we save this and run it.
• 02:01 We get 3 + 2 = 5, right?
• 02:04 That's a little sloppy.
• 02:06 I would maybe take it out of there and instead use a variable result.
• 02:11 And here we can call result and
• 02:13 set it equal to that called method with whatever we passed in.
• 02:19 So, if we save this and run it, again, we'll get the same 3 + 2 = 5.
• 02:24 Now here we're returning something inside of here.
• 02:27 We can do other stuff as well.
• 02:29 So for instance, we could call our display message function
• 02:34 inside of here, it will say program ends.
• 02:37 So let's say program begins instead.
• 02:41 Save this and run it.
• 02:44 Now we see program begins 3 + 2 = 5, right?
• 02:47 because the program flow of this, we start up here,
• 02:51 we call this we pass in our a and b, which then runs this.
• 02:55 The first thing it does is run this, which is this guy.
• 02:58 And then it picks back up here, returns x + y, which comes back here,
• 03:03 gets assigned into results and then output right there.
• 03:07 So a little bit convoluted, but the main thing to remember is,
• 03:10 whenever you want to return a function or a method,
• 03:12 you need to define the data type that you're going to be returning.
• 03:16 So in our case, we're returning an integer, so
• 03:19 this now becomes static int AddThings, whereas before it was static void, right?
• 03:24 And same thing here with passing variables, we can do the same thing,
• 03:27 we could pass a 4 and a 1.
• 03:28 And then maybe down here we need a 4 and a 1.
• 03:32 We don't really need brackets anymore to do that, but same thing.
• 03:37 Now we get 4 + 1 = 5.
• 03:40 And our program knows that because 4 and 1 get passed into this method.
• 03:46 It does the math, it returns it,
• 03:48 which gets assigned to this variable in all as well.
• 03:52 So this a very quick crash course in methods.
• 03:55 There's much more to learn about methods, but you'll pick these things up as we go.
• 03:59 You just need to understand that methods are blocks of code that sit off to
• 04:03 the side, they get executed only when you call them.
• 04:06 And what we do in them is whatever you want.
• 04:09 So again, these are kind of silly examples we have here.
• 04:12 They're not very complicated programs that you normally wouldn't need to break apart
• 04:16 into methods.
• 04:16 But as you go on, methods will become more complicated,
• 04:19 there will be more code in there.
• 04:21 And it's a great way to break apart your programs and keep things separate,
• 04:26 DRY, don't repeat yourself, do it one time, and very cool.
• 04:30 So that's all for this video.
• 04:31 In the next video, we're going to start to look at comparison operators and logic.

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