using System;

public class Program

{

    public static void Main()

    {

        A a = new A();

        Object obj = a;

        if (obj is A)

            Console.WriteLine("1: The object if an instance of A.");

        if (obj.GetType() == typeof(A))

            Console.WriteLine("2: The object if an instance of A.");

    }

}

​

public class A

{

    public A () { }

}