如何在正则表达式中使用字符串变量？ [英] How to use the string variables in regex?

问题描述

搜索元素是一，二，三.......二十



这些元素有不同的可用方式。

one_two

one_two_three

one_two_three_four

one] two [three-four



预期产量是

一二

一二三

一 - 两三四

一二三四



这意味着所有特殊符号替换为（ - ）连字符，

任何可能得到的答案

解决方案

尝试以下代码。



<前lang =cs> 字符串 str = < span class =code-string> one] two [three-four;
str = Regex.Replace（str， [^ 0-9a-zA-Z] +， - ）;

您可以尝试使用 Regex.Replace

请参阅 Regex.Replace方法 [ ^ ]

 类计划
 {
 静态  void  Main（ string  [] args）
 {
  string  s1 =   one_two; 
  string  s2 =   one_two_three; 
  string  s3 =   one_two_three_four; 
  string  s4 =   one] two [三四; 
 
 [更新] 
 正则表达式regex = 新正则表达式（ @   [_ \ [\]]）;  
正则表达式regex =  new 正则表达式（ @  [\\\\]] ）; 
 
  string  result =   ; 
 result = regex.Replace（s1， new  MatchEvaluator（Program.ReplaceWithHyphen））; 
 result = regex.Replace（s2， new  MatchEvaluator（Program.ReplaceWithHyphen））; 
 result = regex.Replace（s3， new  MatchEvaluator（Program.ReplaceWithHyphen））; 
 result = regex.Replace（s4， new  MatchEvaluator（Program.ReplaceWithHyphen））; 
 
} 
 
 [更新] 
 静态  string  ReplaceWithHyphen（匹配m）
 {
  //  返回连字符作为替换如果字符不是字母或数字 
  char  ch = m.Value [ 0 < /跨度>]; 
  if （Char.IsLetterOrDigit（ch））
  return  ch.ToString（ ）; 
  else  
  return     - ; 
} 
} 

Regex + Linq解决方案：

列表< ;串GT; words =  new 列表< string> {  one_two，
   one_two_three，
   one_two_three_four，
  酮] 2 [3-4}; 
 
 
  var  qry = words.Select（w => w =  new 正则表达式（ @ （\]）|（\ [）|（_））。替换（w，   - ））; 

< br $> b $ b

结果：

一二
一二三
一-two-three-four 
 one-two-three-four 

searching elements are one, two, three.......twenty

these elements are available in different possible ways.
one_two
one_two_three
one_two_three_four
one]two[three-four

the expected output is
one-two
one-two-three
one-two-three-four
one-two-three-four

it means all special symbol replace by (-) hyphen,
any possible to get answer

解决方案

Try below code.

string str = "one]two[three-four";
str = Regex.Replace(str, "[^0-9a-zA-Z]+", "-");

You can try to use Regex.Replace
See Regex.Replace Method[^]

class Program
{
    static void Main(string[] args)
    {
        string s1 = "one_two";
        string s2 = "one_two_three";
        string s3 = "one_two_three_four";
        string s4 = "one]two[three-four";

        [UPDATE]
        Regex regex = new Regex(@"[_\[\]]");
        Regex regex = new Regex(@"[\S\s]");

        string result = "";
        result = regex.Replace(s1, new MatchEvaluator(Program.ReplaceWithHyphen));
        result = regex.Replace(s2, new MatchEvaluator(Program.ReplaceWithHyphen));
        result = regex.Replace(s3, new MatchEvaluator(Program.ReplaceWithHyphen));
        result = regex.Replace(s4, new MatchEvaluator(Program.ReplaceWithHyphen));

    }

    [UPDATE]
    static string ReplaceWithHyphen(Match m)
    {
        // Return the hyphen as a replacement if the character is not a letter or digit
        char ch = m.Value[0];
        if (Char.IsLetterOrDigit(ch))
            return ch.ToString();
        else
            return "-";
    }
}

Regex + Linq solution:

List<string> words = new List<string>{"one_two",
            "one_two_three",
            "one_two_three_four",
            "one]two[three-four"};


var qry = words.Select(w=>w = new Regex(@"(\])|(\[)|(_)").Replace(w,"-"));

Result:

one-two
one-two-three
one-two-three-four
one-two-three-four

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