C# if...else语句

using System;

namespace DecisionMaking {

   class Program {

      static void Main(string[] args) {
         /* local variable deFinition */
         int a = 100;

         /* check the boolean condition */
         if (a < 20) {
            /* if condition is true then print the following */
            Console.WriteLine(a is less than 20);
         } else {
            /* if condition is false then print the following */
            Console.WriteLine(a is not less than 20);
         }
         Console.WriteLine(value of a is : {0}, a);
         Console.ReadLine();
      }
   }
}