using System;

class Y{}

class Z{}

​

class AsOperatorExample

{

    static void Main()

    {

        object[] o = new object[5];

        o[0] = new Y();

        o[1] = new Z();

        o[2] = "Hello";

        o[3] = 4759.0;

        o[4] = null;

        for(int q = 0; q<o.Length; ++q)

        {

            string str1 = o[q] as string;

            Console.WriteLine("{0}: ", q);

            if(str1 != null)

            {

                Console.WriteLine("'" + str1 + "'");

            }

            else

            {

                Console.WriteLine("It is not a string");

            }

        }

        Console.WriteLine("===================================");

        if(o[2] is object)

        {Console.WriteLine("o[2] is object");}

        if (o[4] is int)

        {Console.WriteLine("o[4] is an integer");}  

        else

        {Console.WriteLine("o[4] is not an integer");

        Console.ReadLine();

        }

    }

}