using System;

​

public class Program

{

    public static void Main()

    {

        Dog d = new Dog();

        Animal a = d;

        Console.WriteLine("d type={0} className={1}", d.GetType(), d.GetClassName());

        Console.WriteLine("a type={0} className={1}", a.GetType(), a.GetClassName());

        d.Bark();

        // a.Bark();

        // Doesn't work because Animal does not have a Bark method

    }

}

​

class Animal

{

    public virtual string GetClassName()

    {

        return "Animal";

    }

}

​

class Dog : Animal

{

    public override string GetClassName()

    {

        return "Dog";

    }

    public void Bark()

    {

        Console.WriteLine("Woof!");

    }

}