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();
      }
   }
}