How to build a regex w/ new RegExp()

Question

Have an array of local storage keys that looks something like this

[
  '$gl-user',
  '$gl-date-preference::22'
  '$gl-date-preference::28'
  '$gl-mg-filters::22::1'
  '$gl-mg-filters::22::8'
]

First ::_number_ represents the storeId.
Second ::_number_ can represents any additional identifier.

Trying to build a function that takes a storeId and returns all keys that match that storeId. So if 22 was passed in to that function it would return

[
  '$gl-date-preference::22',
  '$gl-mg-filters::22::1',
  '$gl-mg-filters::22::8'
]

Here is my first attempt. Copying this into the console returns null every time but I do not understand why.

var regex = new RegExp('^[$\w\d\-]+\:\:' + '22');
'$gl-mg-filters::22'.match(regex);

Any assistance in getting this regex to work, or ideas on a better solution would be greatly appreciated. Thank you!

score 0 · Accepted Answer · answered Nov 21 '16 at 13:34

Your regex isn't matching, because you're only escaping with the slashes inside of the string. Instead, you should be escaping it twice, e.g.:

var regex = new RegExp('^[$\\w\\d\\-]+\\:\\:' + '22');
'$gl-mg-filters::22'.match(regex);

Your initial attempt would try to compile ^[$wd-]+::22 into a Regex.

How to build a regex w/ new RegExp()

1 Answers1