Polymorphism.java

import java.util.List;
import java.util.LinkedList;

public abstract class Animal 
{
   public abstract void eat();
}

class Fish extends Animal 
{
   @Override
   public void eat() 
   { 
      System.out.println("I eat like a fish!"); 
   }
}

class Goldfish extends Fish 
{
   @Override
   public void eat() 
   { 
      System.out.println("I eat like a goldfish!"); 
   }
}

class Dog extends Animal {
    @Override
   public void eat() 
   { 
      System.out.println("I eat like a dog!"); 
   }
}

public class Program
{
    public static void main(String[] args) {
        List<Animal> animals = new LinkedList<Animal>();

      animals.add(new Fish());
      animals.add(new Goldfish());
      animals.add(new Dog());

      for (Animal currentAnimal : animals) 
      {
         currentAnimal.eat();
      }
    }
}