Methods

Quick reference

• 00:04 Okay, and in this video I want to start to talk about methods.
• 00:06 And methods are an incredibly important part of programming, and
• 00:09 you're going to see them all the time.
• 00:11 They're also called functions in some programming languages.
• 00:13 So, if I call them, accidentally, functions from time to time,
• 00:16 I mean methods.
• 00:17 Methods, functions, they're the same thing.
• 00:19 And a method is a block of code that sort of sits off to the side and
• 00:24 does something.
• 00:25 Now, up until now everything we've done, all the code we've written,
• 00:29 just gets executed whenever we run the program.
• 00:32 We run the program, the code runs, and then it ends.
• 00:35 And that's fine, methods are different.
• 00:38 They don't run unless you specifically call them.
• 00:41 So we'll create it, it'll be sitting there, but
• 00:43 it won't get executed in our program until we specifically say, hey, run that method.
• 00:49 And methods are a little bit complicated, but really not that easy.
• 00:52 Just think of them as blocks of code that sit off to the side that
• 00:56 do something, right?
• 00:57 So, very useful.
• 00:58 And with programming, so often you do the same thing over, and over, and over,
• 01:03 again, in a program.
• 01:04 And you don't want to write that same block of code, over, and over, and
• 01:08 over, again.
• 01:08 You want to write it once and then just call it when you need it, right?
• 01:12 So, it's a principle called DRY, don't repeat yourself.
• 01:16 And it's very important in programming.
• 01:18 So, in this video, we're just going to start to touch on methods.
• 01:21 In the next couple of videos, we'll get into them in more detail.
• 01:24 But this video, I just want you guys to familiarize yourself with them.
• 01:27 And then learn how to create a very basic one, and
• 01:29 then we'll get into more complicated stuff in the next few videos.
• 01:33 So, I'm going to come up here and let's just create an int, and
• 01:37 I'll say a, b, and result.
• 01:40 And let's go a = 3, b = 2, and
• 01:44 result = a + b, all right?
• 01:48 So, here we can Console.WriteLine.
• 01:56 And maybe we want to interpolate this and
• 02:00 let's go,{a} + {b} = {result}.
• 02:05 So, just a very basic program, right?
• 02:10 So, if we save this and run it, we know what's going to happen.
• 02:12 It's going to print out onto the screen, 3 + 2 = 5, right?
• 02:16 And so, here's another example of our code just being executed when we
• 02:19 run the program.
• 02:20 So, let's say after this we want to put a little message
• 02:23 on the screen that says program ended or something.
• 02:26 And we could do it right here.
• 02:27 Let's say we want to create our own method, and
• 02:29 put that little message in there, and then just call the method.
• 02:32 Think very basic method, how would we do that?
• 02:34 So, up until now, we've been doing everything inside of these brackets.
• 02:39 And you'll notice this Main, that's actually a method.
• 02:42 We haven't really talked about that, but Main is actually a method.
• 02:45 So, to create our own method, it's going to look very similar to this.
• 02:48 So, to do that we go, static void.
• 02:52 And we'll talk about void in the next couple of videos.
• 02:54 Don't worry about it, yet.
• 02:55 And now, let's just name this, and let's say DisplayMessage, all right?
• 03:00 And we put our parentheses.
• 03:02 Now, underneath here we put curly brackets, right?
• 03:06 So, you see, this, looks very much like this, right?
• 03:11 It's got the static void, the name of it and curly brackets, static void,
• 03:15 the name and curly brackets.
• 03:17 And inside of these curly brackets, we can do anything we want.
• 03:19 We can write one line of code, two lines of code, 1,000 lines of code,
• 03:23 it doesn't matter.
• 03:24 All of the code that we write in here won't be executed until
• 03:27 we tell the program, specifically, hey, run this method.
• 03:30 So, let's go, I don't know, Console.WriteLine.
• 03:37 And let's say, Program Ends..., all right?
• 03:41 So if we run this, what do you think's going to happen?
• 03:45 Yeah, trick question.
• 03:47 It just says, 3 + 2 = 5.
• 03:49 because like I said, our method doesn't actually run until we tell it to run.
• 03:52 And we haven't told it to run, yet.
• 03:54 We've created the method, but we haven't told our program, hey, run that method.
• 03:58 So, how do we do that?
• 03:59 Well, you just name it.
• 04:00 So, here's the name and
• 04:02 we can come up here into our Main method here, and just go like this.
• 04:07 Now, it will put 3 in a, 2 in b, add up the results, put them on the screen.
• 04:12 Then it will, hey, call this method, which will then do this, all right?
• 04:16 So, if we save this and run it, we see 3 + 2 = 5, program ends.
• 04:23 Very cool and, again, this is a very basic method.
• 04:26 We're not doing much anything here, but
• 04:28 we'll get into more complicated stuff in the next few videos.
• 04:32 So, we can call this as often as we want, right?
• 04:35 So we could call it 3 times, here.
• 04:37 If we run this it will say, 3 + 2 = 5, Program Ends,
• 04:42 Program Ends, Program Ends, right?
• 04:45 We can do other stuff inside of here.
• 04:49 So, maybe, we copy this and do it again, I don't know.
• 04:51 I don't know why you would want to do that, but you can.
• 04:54 You can see, now, 3 + 2 = 5, Program Ends, 3 + 2 = 5, Program Ends.
• 04:59 So, those are methods in a very small nutshell.
• 05:00 We'll get into them in more detail in the next couple of videos.
• 05:03 In the next video, I'll show you how to pass things into your
• 05:06 methods from outside of your methods, and then do stuff with them.
• 05:09 Very interesting, fun stuff, and that'll be in the next video.

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