9 Classes continued

Most Important Concepts / Code

Overloading: two or more methods in the same class with the same name but different signatures

Overriding: having the same method names in a base and in a derived class

Dynamic Method Dispatch

Inheritance:

"is a" relationship

Base / Parent / Super

Derived / Child / Sub

Polymorphism:

Components / implications:

1. Base methods can be overriden in derived classes.

2. Objects of a derived type can be stored in a container declared as the base type.

3. Overriden method code will be executed even from a call that seems to be from base type.

public class Animal

{

public void showSpecies()

{

System.out.println("Regular animal");

}

public void makeSound()

{

System.out.println("Grrrrr");

}

}

public class Dog extends Animal

{

public void showSpecies()

{

System.out.println("Dog");

}

public void makeSound()

{

System.out.println("Woof");

}

}

public class Cat extends Animal

{

public void showSpecies()

{

System.out.println("Cat");

}

public void makeSound()

{

System.out.println("Meow");

}

}

public class Program

{

public static void main(String[] args)

{

Cat felix = new Cat();

Dog fido = new Dog();

Animal[] myPets = { felix, fido };

for (Animal anAnimal : myPets)

{

anAnimal.showSpecies();

anAnimal.makeSound();

}

}

}