Transcript Writing Methods

Writing Methods
Create the method
•
Methods, like functions, do something
•
They contain the code that performs the job
•
Methods have two parts
Create the method
• The first part is called the Header
modifier
return
name
public void message( )
{
open & closing braces
}
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
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”);
}
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
Create a Class
The first part is called the Header
modifier
structure
name
public class MyClass
{
open & closing braces
}
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”);
}
}
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
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
Create an Application
• Syntax:
public class Morty
{
public static void main(String [] args)
{
MyClass mc = new MyClass();
mc.message();
}
}
Compile and Run
• Compile … correct any syntax errors
• Run … check for correct output
– If necessary make any corrections
– Then recompile and rerun.
1-compile
2-run
3-output
• 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
To Edit (add or delete) the PATH of the Windows O/S
0- Start
1- Settings
2Control Panel
3System
4System Properties (dialog box)
5Advanced (tab)
6Environment Variables…
7User (System variables)
You can edit a current variable
You can add/delete
Delimiter is a semi-colon
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”