C#计算给定字符串中的大写和小写字符数

using System;

public class Demo {
   public static void Main() {

      string myStr;
      int i, len, lower_case, upper_case;

      myStr = "Hello";
      Console.Write("String: "+myStr);

      lower_case = 0;
      upper_case = 0;

      len = myStr.Length;

      for(i=0; i<len; i++) {
         if(myStr[i]>='a' && myStr[i]<='z') {
            lower_case++;
         } else if(myStr[i]>='A' && myStr[i]<='Z') {
            upper_case++;
         }
      }
      Console.Write("/nCharacters in lowecase: {0}/n", lower_case);
      Console.Write("Characters in uppercase: {0}/n/n", upper_case);
   }
}