Defining an Interfaces

Declaring Interfaces

The interface keyword is used to declare an interface. Here is a simple example to declare an interface −

Example

Following is an example of an interface −

/* File name : NameOfInterface.java */
import java.lang.*;
// Any number of import statements

public interface NameOfInterface {
   // Any number of final, static fields
   // Any number of abstract method declarations\
}

Interfaces have the following properties −

• An interface is implicitly abstract. You do not need to use the abstractkeyword while declaring an interface.
• Each method in an interface is also implicitly abstract, so the abstract keyword is not needed.
• Methods in an interface are implicitly public.

Example

/* File name : Animal.java */
interface Animal {
   public void eat();
   public void travel();
}