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Is there a RegExp.escape function in JavaScript?

I just want to create a regular expression out of any possible string.

var usersString = "Hello?!*`~World()[]"; var expression = new RegExp(RegExp.escape(usersString)) var matches = "Hello".match(expression); 

Is there a built-in method for that? If not, what do people use? Ruby has RegExp.escape. I don't feel like I'd need to write my own, there have got to be something standard out there.

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Lance Avatar asked Aug 24 '10 22:08

Lance


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1 Answers

The function linked in another answer is insufficient. It fails to escape ^ or $ (start and end of string), or -, which in a character group is used for ranges.

Use this function:

function escapeRegex(string) {     return string.replace(/[-\/\\^$*+?.()|[\]{}]/g, '\\$&'); } 

While it may seem unnecessary at first glance, escaping - (as well as ^) makes the function suitable for escaping characters to be inserted into a character class as well as the body of the regex.

Escaping / makes the function suitable for escaping characters to be used in a JavaScript regex literal for later evaluation.

As there is no downside to escaping either of them, it makes sense to escape to cover wider use cases.

And yes, it is a disappointing failing that this is not part of standard JavaScript.

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bobince Avatar answered Jan 04 '23 04:01

bobince