/**
 * Interface Example One
 * */
public class Main {

	public static void main(String[] args) {

//		new Animal(); // Not Allowed.

		Animal animal = new Dog();
		animal.eat();
		animal.run();
	}
}

interface Animal {

	public static final float pi = 3.14f;

	abstract public void run();

	abstract public void eat();

}

class Dog implements Animal {

	@Override
	public void run() {
		System.out.println("Dog is running");
	}

	@Override
	public void eat() {
		System.out.println("Dog is eating");
	}
}

/*
 *   Rules of Interface
 *       * You cannot create object of interface. They are just a blueprint of a class.
 *       * Use implements keyword
 *       * They can only contain abstract methods.
 *
 *       1. For Methods
 *           * They are public and abstract
 *           * No method body. You cannot write code within your method.
 *
 *       2. For Variables
 *           * Avoid using field variables
 *           * But when used they are constants. Their values cannot be changed once defined.
 *           * They are public, static and final
 *
 * */