/* C#: The Complete Reference by Herbert Schildt Publisher: Osborne/McGraw-Hill (March 8, 2002) ISBN: 0072134852 */ // Demonstrate is. using System; class A {} class B : A {} public class UseIs { public static void Main() { A a = new A(); B b = new B(); if(a is A) Console.WriteLine("a is an A"); if(b is A) Console.WriteLine("b is an A because it is derived from A"); if(a is B) Console.WriteLine("This won't display -- a not derived from B"); if(b is B) Console.WriteLine("B is a B"); if(a is object) Console.WriteLine("a is an Object"); } }