DMD

class Phone {
    void showTime() {
        System.out.println("Phone: Showing time");
    }

    void on() {
        System.out.println("Phone: Turning on");
    }
}

class SmartPhone extends Phone {
    void music() {
        System.out.println("SmartPhone: Playing music");
    }

    @Override
    void on() {
        System.out.println("SmartPhone: Turning on");
    }
}

public class DynamicDemo {
    public static void main(String[] args) {
        // Dynamic method dispatch
        Phone phone1 = new Phone();
        Phone phone2 = new SmartPhone();

        phone1.showTime(); // Calls showTime from Phone class
        phone1.on();       // Calls on from Phone class

        phone2.showTime(); // Calls showTime from Phone class
        phone2.on();       // Calls on from SmartPhone class

        // Additional method specific to SmartPhone
        // phone2.music(); // This line will cause a compilation error

        // To use the music method, you need to declare the object as SmartPhone
        SmartPhone smartPhone = new SmartPhone();
        smartPhone.music(); // Calls music from SmartPhone class
    }
}