Question

编辑： 我有一个string str = "where dog is and cats are and bird is bigger than a mouse"，想要在where和and，and和and，and和句子结尾之间提取单独的子字符串。结果应为：dog is，cats are，bird is bigger than a mouse。（示例字符串可能包含where和and之间的任何子字符串。）

List<string> list = new List<string>();
string sample = "where dog is and cats are and bird is bigger than a mouse";
MatchCollection matches = Regex.Matches(sample, @"where|and\s(?<gr>.+)and|$");
foreach (Match m in matches)
  {
     list.Add(m.Groups["gr"].Value.ToString());
  }

但它不起作用。我知道正则表达不对，所以请帮我纠正。感谢。

Answer 1

"\w+ is"

怎么样？

  List<string> list = new List<string>();
string sample = "where dog is and cat is and bird is";
MatchCollection matches = Regex.Matches(sample, @"\w+ is");
foreach (Match m in matches)
{
    list.Add(m.Value.ToString());
}

示例：https://dotnetfiddle.net/pMMMrU

Answer 2

使用大括号来修复|和后视：

using System;
using System.Text.RegularExpressions;

public class Solution
{
    public static void Main(String[] args)
    {
        string sample = "where dog is and cats are and bird is bigger than a mouse";
        MatchCollection matches = Regex.Matches(sample, @"(?<=(where|and)\s)(?<gr>.+?)(?=(and|$))");
        foreach (Match m in matches)
        {
            Console.WriteLine(m.Value.ToString());
        }
    }
}

小提琴：https://dotnetfiddle.net/7Ksm2G

输出：

dog is 
cats are 
bird is bigger than a mouse

Answer 3

您应该使用MyClass方法而不是Regex.Split()。

Regex.Match()

这将分为字面词string input = "where dog is and cats are and bird is bigger than a mouse"; string pattern = "(?:where|and)"; string[] substrings = Regex.Split(input, pattern); foreach (string match in substrings) { Console.WriteLine("'{0}'", match); }和where。

<强> Ideone Demo

正则表达式找不到所有匹配项

3 个答案: