Writing Methods

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Writing Methods
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Create the method

• Methods, like functions, do something
• They contain the code that performs the job
• Methods have two parts

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Create the method

• The first part is called the Header
• modifier return name
• public void message( )
• open closing braces

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Methods have two parts

• The second part is called the Body
• The body contains the lines of code that instruct
  the computer what to do
• You can have as many lines of code in the body as
  you want

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Methods have two parts

• This Body has one line of code
• It tells the computer to print to the screen the
  text that is inside the set of double quotes
• public void message( )
• System.out.println()
• System.out.println(java is not kawfy)

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Create a Class

• To use the method we need to create a simple
  class
• We put the method inside the class
• The class can have as many methods as you wish
• The class also has a Header and a Body

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Create a Class

• The first part is called the Header
• modifier structure name
• public class MyClass
• open closing braces

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Create a Class

• The second part is called the Body
• The body contains one or more methods
• public class MyClass
• public void message()
• System.out.println()
• System.out.println(java is not kawfy)

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Create an Application

• An Application is an executable program
• It uses the methods of different classes to
  execute the program
• Some methods are from the Java Class Library
• Other methods are from the Classes that We wrote

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Create an Application

• We will create an object (instance) of the class
• We will call (invoke) a method of the class
• The Application class also has a Header and a
  Body
• The Application has one method named main

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Create an Application

• Syntax
• public class Morty
• public static void main(String args)
• MyClass mc new MyClass()
• mc.message()

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Compile and Run

• Compile correct any syntax errors
• Run check for correct output
• If necessary make any corrections
• Then recompile and rerun.

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1-compile
2-run
3-output
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• You will need to download a text editor
• You will need to download the latest version of
  Java
• You will need to reset the Path variable
• You will then be ready to roll

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To Edit (add or delete) the PATH of the Windows
O/S 0- Start 1- Settings 2- Control
Panel 3- System 4- System Properties
(dialog box) 5- Advanced (tab) 6-
Environment Variables 7- User (System
variables) You can edit a current variable You
can add/delete Delimiter is a semi-colon
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• The Path should be edited by inserting the
• following line at the very beginning
• C\ program files\java\jdk1.5.0_06\bin
• Make sure you put the semi-colon (delimiter)
  right
• after the word bin