C#嵌套循环

using System;

namespace Loops {
   class Program {
      static void Main(string[] args) {
         /* local variable definition */
         int i, j;

         for (i = 2; i < 100; i++) {
            for (j = 2; j <= (i / j); j++)
            if ((i % j) == 0) break; // if factor found, not prime
            if (j > (i / j)) Console.WriteLine("{0} is prime", i);
         }
         Console.ReadLine();
      }
   }
}