Question

I am trying to find a way to determine which character in my string does not match the regex, is there a way to do so in Javascript?

I’ve been using the regex object and i was able to determine whether a string matches the regex but i would like to go step further to determine why a string does not match the regex.

any thoughts?

This was what I currently have … i am just trying to make sure
a string only contains the set of characters found in the following regex …
and i would like to see which character does not match.

Here’s my code :

var regexTest = new RegExp("^[0-9a-zA-Z\\!\\040\\@\\s\\#\\$\\%\\&\\*\\(\\)\\_\\+\\:\\\"\\<\\>\\?\\-\\=\\;\\'\\,\\.\\\\]+$",g);

var bValid = regexTest.test(value); //this will check whether the value is valid ... 

I’ve tried using value = value.replace(regexTest,''), but was unable to actually filter out the characters.

Answer 1

You could replace all the characters that do match with '', leaving only the things that don’t match:

'abc123'.replace(/([a-z]+)/g, '')
// "123"