Introduction to Java Method Writing

1. Writing Methods

2. Create the method • A Method is a tool to do something • It contains the code that performs the job • Methods have two parts

3. Create the method • The first part is called the Header modifierreturnname public void message( ) { open & closing braces }

4. Methods have two parts • The second part is called the Body • The bodycontains 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

5. Methods have two parts • ThisBody has two lines of code • It tells the computer to print to the screen the text that is inside the set of doublequotes after skipping a blank line public void message( ) { System.out.println(); System.out.println(“java is not kawfy”); }

6. Create a Class • To use the method we need to create a simple class • The class is like a tool bag • It can hold one or many tools (methods) • The class also has a Header and a Body

7. Create a Class The first part is called the Header modifierstructurename public class MyMethods { open & closing braces }

8. Create a Class The second part is called the Body The body contains one or more methods public class MyMethods { public void message() { System.out.println(); System.out.println(“java is not kawfy”); } }

9. 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

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

11. Create an Application • Syntax: public class RunMyMethods { public static void main(String [] args) { MyMethods mm = new MyMethods(); mm.message(); //class object calls method } }

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