Java — Polymorphism

What is polymorphism?

One interface, multiple implementations.

Method overriding

class Animal {
    void sound() {
        System.out.println("Some sound");
    }
}

class Dog extends Animal {
    @Override
    void sound() {
        System.out.println("Bark");
    }
}

class Cat extends Animal {
    @Override
    void sound() {
        System.out.println("Meow");
    }
}

Runtime polymorphism

Animal myAnimal = new Dog();
myAnimal.sound();  // Bark

myAnimal = new Cat();
myAnimal.sound();  // Meow

Mini Practice

1. Override methods
2. Use parent reference
3. Call overridden methods
4. Practice polymorphism

Up Next

Continue with Abstraction - Abstract classes.