c# - 反转字符串中的单词，标点符号除外

Question

给定一个字符串

"hello there, compiler."

如何颠倒每个单词，除了标点符号。所以完成后将打印:

"olleh ereht, relipmoc." 

而不是 “olleh ,ereht .relipmoc”

我的代码(忽略标点符号):

 static string ReverseString(string s)
 {
     StringBuilder sb = new StringBuilder();
     string[] words = s.Split(' ');

     foreach (var word in words)
     {
         for (int i = word.Length - 1; i >= 0; i--)
         {
             sb.Append(word[i]);
         }

         sb.Append(" ");
     }

     return sb.ToString();
 }

Answer 1

我建议 Split(技巧:不仅在空格上，而且在非单词符号上——空格、逗号、点等)，修改和最终 Concat:

  using using System.Text.RegularExpressions;

  ...

  string source = @"hello there, compiler.";

  string result = string.Concat(Regex
    .Split(source, @"(\W+)") // split on not word letter, separator preserved
    .Select(letter => letter.Length > 0 && char.IsLetter(letter[0]) 
       ? string.Concat(letter.Reverse()) // reverse letter
       : letter));                       // keep separator intact 

  Console.Write(result);

结果:

  olleh ereht, relipmoc.