如何获得正则表达式匹配在字符串中的位置? [英] How to get the position of a Regex match in a string?

问题描述

我知道如何使用preg_match和preg_match_all查找给定字符串中的正则表达式模式的实际匹配项，但是我编写的函数不仅需要匹配项的文本，还需要能够遍历字符串匹配...

I know how to use preg_match and preg_match_all to find the actual matches of regex patterns in a given string, but the function that I am writing not only needs the text of the matches, but to be able to traverse the string AROUND the matches...

因此，我需要根据正则表达式模式了解匹配在字符串中的位置.

Therefore, I need to know the position of the match in the string, based on a regex pattern.

我似乎找不到类似于strpos()的允许正则表达式的函数...任何想法吗?

I can't seem to find a function similar to strpos() that allows regex...any ideas?

推荐答案

您可以使用标志

You can use the flag PREG_OFFSET_CAPTURE for that:

preg_match('/bar/', 'Foobar', $matches, PREG_OFFSET_CAPTURE);
var_export($matches);

结果是:

array (
  0 => 
  array (
    0 => 'bar',
    1 => 3,     // <-- the string offset of the match
  ),
)

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在以前的版本中，此答案在正则表达式(preg_match('/(bar)/', ...))中包含捕获组.从前几条评论中可以明显看出，这使某些人感到困惑，此后已由@Mikkel进行了编辑.请忽略这些评论.

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In a previous version, this answer included a capture group in the regular expression (preg_match('/(bar)/', ...)). As evident in the first few comments, this was confusing to some and has since been edited out by @Mikkel. Please ignore these comments.

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