recognize phone number using "()" for area code

Question

I need to recognize a phone number on a long string, now I am using this regex

(((\d)(-)?)+){7,15}|\*\d{3,10}|\d{3,10}\*

but that does not recognize any one of these formats:

(734) 555 1212
(734) 555.1212
(734) 555-1212
(734) 5551212
(734)5551212

with "()",

How can I change it to support also these formats?

Answer 1

You can use this updated regex:

\(\d{3}\)\s*\d{3}[\s.-]?\d{4}\b|\*\d{3,10}|\d{3,10}\*

See demo

Explanation of the updated part:

• \( - literal round brackets
• \d{3} - match 3 digits
• \) - closing round bracket
• \s* - optional whitespace
• \d{3} - 3 digits
• [\s.-]? - 0 or 1 whitespace or dot or hyphen
• \d{4} - 4 digits.

Answer 2

Your regular expression is very lenient - it will recognize 1-2-3-4-5-6-7- as a valid phone number, which would of course be a false positive. If you would like to keep the same level of leniency, replace the optional dash - in your expression with an optional character group that includes parentheses, spaces, and a dash:

[(]?(((\d)([() .-]+)?)+){7,18}|\*\d{3,10}|\d{3,10}\*

Demo.

Of course this expression will bring even more false positives, because it accepts anything that looks remotely close to a phone number.