C#计算字符串中的单词数

using System;

public class Demo {
   public static voID Main() {
      int a = 0 , myWord = 1;
      string str = "Hello World!";
      while (a <= str.Length - 1) {
         if(str[a]==' ' || str[a]=='\n' || str[a]=='\t') {
            myWord++;
         }
         a++;
      }
      Console.Write("Number of words in the string = {0}\n", myWord);
   }
}