using System;

​

public class A

{

    public virtual void Method1()

    {

        // Do something.

        Console.WriteLine("Do Something");

    }

}

​

public class B : A

{

    public override void Method1() 

    {

        // Do something else.

        Console.WriteLine("Do Something Else");

    }

}

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        A objectA = new A();

        B objectB = new B();

        objectA.Method1();

        objectB.Method1();

    }

}