如何在 JavaScript Regexp 中捕获任意数量的组? [英] How to capture an arbitrary number of groups in JavaScript Regexp?

问题描述

我希望这行 JavaScript:

I would expect this line of JavaScript:

"foo bar baz".match(/^(s*w+)+$/)

返回如下内容:

["foo bar baz", "foo", " bar", " baz"]

但它只返回最后捕获的匹配项:

but instead it returns only the last captured match:

["foo bar baz", " baz"]

有没有办法获取所有捕获的匹配项?

Is there a way to get all the captured matches?

推荐答案

当你重复一个捕获组时，在大多数风格中，只保留最后一个捕获；任何先前的捕获都会被覆盖.在某些风味中，例如.NET，您可以获得所有中间捕获，但 Javascript 不是这种情况.

When you repeat a capturing group, in most flavors, only the last capture is kept; any previous capture is overwritten. In some flavor, e.g. .NET, you can get all intermediate captures, but this is not the case with Javascript.

也就是说，在 Javascript 中，如果您有一个包含 N 个捕获组的模式，则每个匹配项只能准确捕获 N 个字符串，即使其中一些组是重复.

That is, in Javascript, if you have a pattern with N capturing groups, you can only capture exactly N strings per match, even if some of those groups were repeated.

所以一般来说，取决于你需要做什么:

So generally speaking, depending on what you need to do:

• 如果它是一个选项，请改为使用分隔符拆分
• 可能匹配 /(pattern)+/ 而不是匹配 /pattern/g，也许在 exec 循环中
  • 请注意，这两者并不完全相同，但可能是一种选择
  • If it's an option, split on delimiters instead
  • Instead of matching /(pattern)+/, maybe match /pattern/g, perhaps in an exec loop
    • Do note that these two aren't exactly equivalent, but it may be an option
    • 在一场比赛中捕获重复的组
    • 然后运行另一个正则表达式来分解匹配
    • regular-expressions.info/重复捕获组与捕获重复组
      • Javascript 风味说明

      这是一个在文本中匹配 的示例，使用 exec 循环，然后在 ; 获取单个单词(另见 ideone.com):

      Here's an example of matching <some;words;here> in a text, using an exec loop, and then splitting on ; to get individual words (see also on ideone.com):

      var text = "a;b;<c;d;e;f>;g;h;i;<no no no>;j;k;<xx;yy;zz>";
      
      var r = /<(w+(;w+)*)>/g;
      
      var match;
      while ((match = r.exec(text)) != null) {
        print(match[1].split(";"));
      }
      // c,d,e,f
      // xx,yy,zz
      

      使用的模式是:

            _2__
           /    
      <(w+(;w+)*)>
       \__________/
            1
      

      这匹配、、等.2 重复捕获任意数量的单词，但只能保留最后一次捕获.整个单词列表由第 1 组捕获；这个字符串然后在分号分隔符上split.

      This matches <word>, <word;another>, <word;another;please>, etc. Group 2 is repeated to capture any number of words, but it can only keep the last capture. The entire list of words is captured by group 1; this string is then split on the semicolon delimiter.

      • 如何访问匹配的组在 javascript 正则表达式中?

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