class Phone {

public void on() {

System.out.println("Starting the phone....");

}

public void greetings() {

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

}

}

class SmartPhone extends Phone {

public void on() {

System.out.println("Starting the Smart Phone...");

}

public void music() {

System.out.println("Playing Music....");

}

}

class A {

void callme() {

System.out.println("Inside A's callme method");

}

}

class B extends A {

// override callme()

void callme() {

System.out.println("Inside B's callme method");

}

}

class C extends A {

// override callme()

void callme() {

System.out.println("Inside C's callme method");

}

}

public class DynamicMethodDispatch {

public static void main(String[] args) {

// dynamic dispatch

// runtime polymorphism

Phone obj = new SmartPhone();

obj.on();//Starting the Smart Phone...

// obj.music();//It will show an error

A a = new A(); // object of type A

B b = new B(); // object of type B

C c = new C(); // object of type C

A r; // obtain a reference of type A

r = a; // r refers to an A object

r.callme(); // calls A's version of callme

r = b; // r refers to a B object

r.callme(); // calls B's version of callme

r = c; // r refers to a C object

r.callme(); // calls C's version of callme

}

}