复制Java的“Pattern.quote”的功能。在一个JavaScript的RegExp [英] Replicate the functionality of Java's "Pattern.quote" in a JavaScript RegExp

问题描述

在Java中，你可以尝试使用 Pattern.compile（stackoverflow.com）来匹配URL stackoverflow.com 的正则表达式。 ）。但这是错误的，因为。在正则表达式中有特殊含义。解决这个问题的最简单的方法是写出 Pattern.compile（Pattern.quote（stackoverflow.com）），它出现在： Pattern中。编译（\\Qstackoverflow.com\\\E）其中quotes整个字符串。

我想在JavaScript中做同样的事情，但JavaScript的正则表达式不会为<$​​ c $ c> \ Q 和 \E ，它看起来不像是JavaScript的等价物，所以我不知道如何去做。我的第一个想法（请参阅下面的答案）是在JavaScript正则表达式中，在任何具有特殊含义的字符前面加一个反斜杠，但这似乎有潜在的错误倾向，我怀疑有人可能知道更好的方法。 >

这是一个Firefox扩展，所以特定于Mozilla的解决方案是可以的。

解决方案

详细说明我的建议，它看起来像这样：

  // RegExp匹配所有的字符有一个RegExp 
中的特殊含义var regexpSpecialChars = /（[\ [\] \ ^ \ $ \ | \（\）\\\\\\\\\\\\\\\\\\\\\\\\\\' ！\\ {\} \ = \]）/ GI; 
  

我不确定这是否正确，因为某些字符（如！和 = ）在某些情况下似乎只有特殊的含义。但假设它是，那么你会做
$ b $ pre $ var $ quotedURL = url.replace（regexpSpecialChars，'\\ $ 1' ）;

来取代所有 $ 用 \ $ 的。然后你可以从 quotedURL ：

  var myRegExp =新的RegExp（quotedURL，'gi'）; 
  

In Java, you might try to make a regular expression that would match the URL stackoverflow.com using Pattern.compile("stackoverflow.com"). But this would be wrong because the . has special meaning in regular expressions. The easiest way to fix this is to write Pattern.compile(Pattern.quote("stackoverflow.com")) which comes out to: Pattern.compile("\\Qstackoverflow.com\\E") which "quotes" the entire string.

I want to do the same thing in JavaScript, but JavaScript's regular expressions don't assign any meaning to \Q and \E and it doesn't look like there is a JavaScript equivalent, so I'm not sure how to go about it. My first thought (see my answer below) is to just put a backslash before any character that has a special meaning in a JavaScript regex, but this seems potentially error-prone and I suspect that someone might know of a better way.

This is for a Firefox extension so Mozilla-specific solutions are okay.

解决方案

To elaborate on my suggestion, it would look something like this:

// A RegExp that matches all the characters which have a special meaning in a RegExp
var regexpSpecialChars = /([\[\]\^\$\|\(\)\\\+\*\?\{\}\=\!])/gi;

I'm not sure if this is quite right, since some characters (like ! and =) only seem to have special meaning in certain situations. But assuming that it is, then you would do

var quotedURL = url.replace(regexpSpecialChars, '\\$1');

to replace, for instance, all $'s with \$'s. Then you can just build the RegExp from quotedURL:

var myRegExp = new RegExp(quotedURL, 'gi');

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