文字列を反転する C# プログラム

myStr = "Tom";

// find string length
int len;
len = myStr.Length - 1;

while (len >= 0) {
   rev = rev + myStr[len];
   len--;
}

using System;
class Demo {
   static void Main() {
      string myStr, rev;
      myStr = "Tom";
      rev ="";
      Console.WriteLine("String is {0}", myStr);
      // find string length
      int len;
      len = myStr.Length - 1;
      while (len >= 0) {
         rev = rev + myStr[len];
         len--;
      }
      Console.WriteLine("Reversed String is {0}", rev);
      Console.ReadLine();
   }
}

String is Tom
Reversed String is moT