using System;

using System.Collections;

​

public abstract class Animal

{

    protected string name;

    public string Name

    {

        get { return name; }

        set { name = value; }

    }

    public Animal()

    {

        name = "The animal with no name";

    }

    public Animal(string newName)

    {

        name = newName;

    }

    public void Feed()

    {

        Console.WriteLine( name + "has been fed.");

    }

}

​

public class Cow : Animal

{

    public void Milk()

    {

        Console.WriteLine(name + "{name} has been milked.");

    }

    public Cow(string newName) : base(newName) {}

}

​

public class Chicken : Animal

{

    public void LayEgg()

    {

        Console.WriteLine(name+ "{name} has laid an egg.");

    }

    public Chicken(string newName) : base(newName) {}

}

​

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Create an Array type collection of Animal " +

                  "objects and use it:");

        Animal[] animalArray = new Animal[2];

        Cow myCow1 = new Cow("Lea");

        animalArray[0] = myCow1;

        animalArray[1] = new Chicken("Noa");

        foreach (Animal myAnimal in animalArray)

        {

            Console.WriteLine("New {" + myAnimal.ToString()+ "} object added to Array collection, Name = {+"+myAnimal.Name+"}");

        }

        Console.WriteLine("Array collection contains {"+animalArray.Length+"} objects.");

        animalArray[0].Feed();

        ((Chicken)animalArray[1]).LayEgg();

        Console.WriteLine();

        Console.WriteLine("Create an ArrayList type collection of Animal " +

                  "objects and use it:");

        ArrayList animalArrayList = new ArrayList();

        Cow myCow2 = new Cow("Rual");

        animalArrayList.Add(myCow2);

        animalArrayList.Add(new Chicken("Andrea"));

        foreach (Animal myAnimal in animalArrayList)

        {

            Console.WriteLine("New {"+myAnimal.ToString()+"} object added to ArrayList collection," +

                      " Name = {"+myAnimal.Name+"}");

        }

        Console.WriteLine("ArrayList collection contains {"+animalArrayList.Count+"} " 

                  + " objects.");

        ((Animal)animalArrayList[0]).Feed();

        ((Chicken)animalArrayList[1]).LayEgg();

        Console.WriteLine();

        Console.WriteLine("Additional manipulation of ArrayList:");

        animalArrayList.RemoveAt(0);

        ((Animal)animalArrayList[0]).Feed();

        animalArrayList.AddRange(animalArray);

        ((Chicken)animalArrayList[2]).LayEgg();

        Console.WriteLine("The animal called {"+myCow1.Name+"} is at " +

                          "index {"+animalArrayList.IndexOf(myCow1)+"}.");

        myCow1.Name = "Mary";

        Console.WriteLine("The animal is now " +

                  "called {"+((Animal)animalArrayList[1]).Name+"}.");

    }

}