Dollar sign US phone number regex

Question

I just need to know why the dollar sign is needed at the end of the regex for validating US phone numbers

function telephoneCheck(str) {

return (/^(1)?(\s)?(\(\d{3}\)|\d{3})[\s-]?\d{3}[\s-]?\d{4}$/).test(str) 

}
console.log(telephoneCheck("551-555-5555"));

That doesn't validate the number, it just checks whether it fits a certain pattern. ;-) — RobG, Feb 07 '20 at 05:13

score 2 · Accepted Answer · edited Feb 07 '20 at 07:48

2

^ is start of string and $ is end of string.

Therefore we want to match only this string, not a substring within a larger string.

Fully explained:

^ assert the start of the string
(1)? zero or one "1"
(\s)? zero or one whitespace character
($\d{3}$|\d{3}) 3 digits in () or 3 digits
[\s-]? zero or one whitespace or "-"
\d{3} 3 digits
[\s-]?zero or one whitespace or "-"
\d{4} 4 digits
$ end of string

On regex101

With:

Without:

edited Feb 07 '20 at 07:48

deef0000dragon1

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answered Feb 07 '20 at 04:44

Ryan Schaefer

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Great explanation cheers! – endlessLearning Feb 07 '20 at 04:49

Dollar sign US phone number regex

1 Answers1