using System;using System.Collections.Generic;using System.Linq;using System.Text;

namespace ConsoleApplication12{ class ParentClass { public virtual void Display() { Console.WriteLine("Base Class"); } } class ChildClass:ParentClass { public override void Display() { base.Display(); Console.WriteLine("derived class"); } }

class Program {

static void Main(string[] args) { ChildClass cc = new ChildClass(); cc.Display(); Console.ReadLine(); } }}