Java Interface Example



/*

Java Interface example.

This Java Interface example describes how interface is defined and

being used in Java language.



Syntax of defining java interface is,

interface {

//members and methods()

}

*/



//declare an interface

interface IntExample{



/*

Syntax to declare method in java interface is,

methodName();

IMPORTANT : Methods declared in the interface are implicitly public and abstract.

*/



public void sayHello();

}

}

/*

Classes are extended while interfaces are implemented.

To implement an interface use implements keyword.

IMPORTANT : A class can extend only one other class, while it

can implement n number of interfaces.

*/



public class JavaInterfaceExample implements IntExample{

/*

We have to define the method declared in implemented interface,

or else we have to declare the implementing class as abstract class.

*/



public void sayHello(){

System.out.println("Hello Visitor !");

}



public static void main(String args[]){

//create object of the class

JavaInterfaceExample javaInterfaceExample = new JavaInterfaceExample();

//invoke sayHello(), declared in IntExample interface.

javaInterfaceExample.sayHello();

}

}



/*

OUTPUT of the above given Java Interface example would be :

Hello Visitor !

*/