WEBVTT

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In this demo I'm going to show you an example of

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calling a method which in turn

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calls another method as it runs

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I have the methodsdemo project open

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and I'm going to use the CodePad for this.

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The methodsdemo project has a class MethodsDemo

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which just has a couple of methods

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method one and method two

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lets look at method two first

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it doesn't do much at all just prints out a message

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in method two.

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Lets create and instance of MethodsDemo

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I could do this in the object bench or in the CodePad

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here I'm going to do it in the CodePad

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so lets declare

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a variable m of type MethodsDemo

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and create a new MethodsDemo object

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now I can call the method, method two

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of that object

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and execute that and that just opens a terminal window

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and outputs the message that you would expect it to.

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I'm going to clear the terminal window because I want

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to be sure that the next time I call a method

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I'm only seeing the output from that method and not

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from the previous method call.

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Lets take a look at the other method

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in the MethodsDemo class, method one

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this prints out a message

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and then immediately calls method two

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after that it prints out another message

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so lets try running that

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m dot method one

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and again it opens the terminal window

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and outputs some messages.

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Lets think about whats going on here

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the first line of output was produced by

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a System dot out dot println statement in method one

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the second line of output though is the same as we saw

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when I called method two directly

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this line is not produced by a statement in method one

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it is produced by a System dot out dot println statement

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in method two.

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This happens because method one called method two

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once method two completes then

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the code in method one continued and produced

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this final line of output.

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if I look at the code again

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we can see whats happened

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I called method one this line executed

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then this line, but this line

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calls to method two so from here

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the execution of the code jumps into method two

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and this line of code is executed

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and it outputs the message in method two

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when this method completes

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execution of code jumps back into

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method one immediately after the call to method two

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and this final line in method one executes.

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In an object orientated program

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its very common for a method

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to call another method

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which in turn may even call another method and so on

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so its very important to understand the way

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these method calls work.