Javascript equivalent of Perl's \Q ... \E or quotemeta()

Question

In Perl regular expressions, you can surround a subexpression with \Q and \E to indicate that you want that subexpression to be matched as a literal string even if there are metacharacters in there. You also have the quotemeta function that inserts exactly the right number of backslashes in a string so that if you subsequently interpolate that string into a regular expression, it will be matched literally, no matter what its contents were.

Does Javascript (as deployed in major browsers) have any built in equivalent? I can write my own just fine, but I would like to know if I don't have to bother.

Answer 1

There is no such built-in feature.

Rather than implementing your own, I advise you look into the multitude of regex escape functions available on the internet.

That page proposes the following solution (by Colin Snover):

RegExp.escape = function(text) {
    return text.replace(/[-[\]{}()*+?.,\\^$|#\s]/g, "\\$&");
}

or advises to use the XRegExp library.

Answer 2

Quotemeta isn't implemented natively as far as I know, but I've used this a few months ago for just this:

function quotemeta (str) {
  // http://kevin.vanzonneveld.net
  // +   original by: Paulo Freitas
  // *     example 1: quotemeta(". + * ? ^ ( $ )");
  // *     returns 1: '\. \+ \* \? \^ \( \$ \)'
  return (str + '').replace(/([\.\\\+\*\?\[\^\]\$\(\)])/g, '\\$1');
}

From http://phpjs.org/functions/quotemeta:496