c# Regex

using System;
using System.Text.RegularExpressions;

public class Test
{

    public static void Main ()
    {

      // Define a regular expression for currency values.
      Regex rx = new Regex(@"^-?/d+(/./d{2})?$");
     
      // Define some test strings.
      string[] tests = {"-42", "19.99", "0.001", "100 USD"};
     
      // Check each test string against the regular expression.
      foreach (string test in tests)
      {
          if (rx.IsMatch(test))
          {
              Console.WriteLine("{0} is a currency value.", test);
          }
          else
          {
              Console.WriteLine("{0} is not a currency value.", test);
          }
      }
    
    }

}

 

 使用正则表达式检查字符串中重复出现的词

 

 

using System;
using System.Text.RegularExpressions;

public class Test
{

    public static void Main ()
    {

        // Define a regular expression for repeated words.
        Regex rx = new Regex(@"/b(?<word>/w+)/s+(/k<word>)/b",
          RegexOptions.Compiled | RegexOptions.IgnoreCase);

        // Define a test string.       
        string text = "The the quick brown fox  fox jumped over the lazy dog dog.";
       
        // Find matches.
        MatchCollection matches = rx.Matches(text);

        // Report the number of matches found.
        Console.WriteLine("{0} matches found.", matches.Count);

        // Report on each match.
        foreach (Match match in matches)
        {
            string word = match.Groups["word"].Value;
            int index = match.Index;
            Console.WriteLine("{0} repeated at position {1}", word, index);  
        }
       
    }

}