如何在JS的正则表达式中将用户输入用作量词? [英] How to use user input as an Quantifier in Regex in JS?

问题描述

我的尝试是:

var re = new RegExp("\w{" + n + "}", "g");

但是它似乎没有用.

P.S. -我搜索了Stackoverflow的几个问题，以为它一定是在以前被问过的.但是我没有找到一个，所以我问了我一个问题.

P.S. - I have searched several questions of Stackoverflow thinking it must have been asked before But I didn't find one, so I asked my question.

推荐答案

问题在于，\不仅是正则表达式中的转义字符，而且还是JS字符串中的转义字符.因此，当您从字符串创建正则表达式时，需要对其进行转义.这意味着\w在字符串中变成"\\w"，如果要匹配单个\，它甚至会变成"\\\\".

The problem is that \ is not only the escape character in regex but also in JS strings. So when you create a regular expression from a string you need to escape it. This means that \w becomes "\\w" in a string and if you want to match a single \ it would even become "\\\\".

如果您不关心字符或字符串之前是否经过验证，也可以使用.而不是将其更改为\\w.

Instead of changing it to \\w you can also use . if you don't care about the characters or if the string was validated before.

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