using System;
public class Program
{
public static void Main()
Base objBase = new Base();
objBase.Message(); // I amd Base
Derived objDerived = new Derived();
objDerived.Message(); // I am Derived
// Now, set the reference of derived class to base class.
objBase = new Derived();
objBase.Message(); // I am Base
}
public class Base
public virtual void Message()
Console.WriteLine("I am Base");
public class Derived : Base
public override void Message()
Console.WriteLine("I am Derived");