正则表达式的用法

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;

namespace RegexDemo
{
    class Program
    {
        static void Main(string[] args)
        {
            //string str = "2345 2346666";
            //string pattern = @"(?<aa>23(?:45|46))";
            string str = "student  disposition close open successs support";
            string pattern = @"(?<aa>(\bs\S*))\D*(?<bb>(close))";
            string pattern2 = @"\b\S*\b";
            string pattern3 = @"(.)\1";//匹配2个相同的字符
            Regex va = new Regex(pattern3);
          MatchCollection mm= va.Matches(str);
          foreach (Match theMatch in mm)
          {
             //Console.WriteLine(theMatch.Groups["aa"]);
              //Console.WriteLine(theMatch.Groups["bb"]);
              Console.WriteLine(theMatch.Value);
          }
           Console.ReadKey();
        }
    }
}