A simple example

• A simple example of extending a base Animal class:

  public abstract class Animal
  {
    protected boolean hasColdNose;
  
    public abstract String speak();
  
    public void setHasWetNose(boolean hasColdNose) {
      this.hasColdNose = hasColdNose;
    }
    public boolean hasColdNose() {
      return hasColdNose;
    }
  }
  
  public class Dog extends Animal
  {
    public Dog() {
      hasColdNose = true;
    }
    public String speak() {
      return "woof";
    }
  }
  
  public class Bird extends Animal
  {
    public Bird() {
      hasColdNose = false;
    }
    public String speak() {
      return "chirp";
    }
  }
  

  public class Main
  {
    public Main() {
      Animal fido = new Dog();
      Animal bigbird = new Bird();
      System.out.println( "fido says " + fido.speak() );
      System.out.println( "bigbird says " + bigbird.speak() );
    }
  
    public static void main(String[] args) {
      new Main();
    }
  }