using System;

public class Program

{

    public static void Main()

    {

        object objNull = null;

        Console.WriteLine("Convert null value : {0}", Convert.ToString(null));

        Console.WriteLine("Convert null object : {0}", Convert.ToString(objNull));

        Console.WriteLine("convert null is equal to string empty ? : {0}",Convert.ToString(Convert.ToString(null) == string.Empty));

        Console.WriteLine("convert null object is equal to string empty ? : {0}",Convert.ToString(Convert.ToString(objNull) == string.Empty));

    }

}