Interfaces in Java

Interfaces specify what a class must do and not how. It’s a way to achieve abstraction in Java.

Source Code

interface Animal {
    public void animalSound(); // interface method (does not have a body)
    public void run(); // interface method (does not have a body)
}
class Pig implements Animal {
    public void animalSound() {
        // The body of animalSound() is provided here
        System.out.println("The pig says: wee wee");
    }
    public void run() {
        // The body of run() is provided here
        System.out.println("The pig runs");
    }
}