Regex accepting spaces before and after string

Question

I'm trying to do a regex which accepts a string containing 3-10 characters (white spaces before and after the string are allowed).

Why does this:

return (this.state.user.name.match(`^\s*([a-zA-Z0-9.\-_]{3,10})\s*$`));

returns false when I try to put white space(s) before and/or after the string? (it works correctly if I don't put white spaces.)

I am probably missing something, because it works using the regex tester: https://regex101.com/r/2371SM/1

Thanks for your help.

Are you sure that the variable has spaces and is not trimmed? — Rahul Desai
– Rahul Desai, Commented Apr 27, 2018 at 20:54

dave · Accepted Answer · 2018-04-27 20:56:54Z

3

When you pass the regex as a string you have to do double \\ so that you are escaping the \ and not the letter that follows it:

console.log(((" abcd").match(`^\\s*([a-zA-Z0-9.\-_]{3,10})\\s*$`)));

console.log(((" abcd").match(/^\s*([a-zA-Z0-9.\-_]{3,10})\s*$/)));

answered Apr 27, 2018 at 20:56

dave

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You made my day. Thank you.