View difference between Paste ID: An44NA7U and SvR6xVCa

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 
 namespace UseDoubleAlias
 {
     class Program
     {
         static void Main(string[] args)
         {
             object value = 23.5;
 
             // "is" operator checks if given value can be converted to
             // given type.
             // Converting from object to other type - unboxing.
             // Note: Unboxing is one of the supported operations of
             // "is" operator.
             // See here for more on "is": http://msdn.microsoft.com/en-us/library/scekt9xw%28v=vs.71%29.aspx
             if (value is Double)
             {
                 Console.WriteLine(value + " is Double.");
             }
             else
             {
                 Console.WriteLine(value + " is not Double.");
             }
 
             if (value is System.Double)
             {
                 Console.WriteLine(value + " is System.Double.");
             }
             else
             {
                 Console.WriteLine(value + " is not System.Double.");
             }
         }
     }
 
     //Note: System.Double is struct but this is not so important in this example.
     class Double
     {
         // Empty class(type) having the same name as System.Double.
     }
 }