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.
Best Answer
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:
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.