I'm trying to make a regex which can match a phone number and so tell me if the phone number is either valid or not.
I would like to verify if there is a country id before the phone number, this one is well formated.
For example : +(33)0123456789 I want to be sure if the user start to type the first parenthesis it must be followed by number and ended by a closing parenthesis.
I have succeeded with PCRE engine
^[+]?((\()?(?(2)[0-9]{1,4})(?(2)\)))?([0-9]{2}){1}([\.\- ]?[0-9]{2}){4}$
But I realized this way doesn't work with javascript engine, conditional is not supported.
^[+]?((\()?((?=\2)[0-9]{1,4})((?=\2)\)))?([0-9]{2}){1}([\.\- ]?[0-9]{2}){4}$
It doesn't fill my needs. I want to check if the first parenthesis is set then it must be followed by number and a closing parenthesis.
So I ask you if there is a workaround in javascript to do this ?
Some help would be really appreciated, thank you :)
The ((\()?(?(2)[0-9]{1,4})(?(2)\)))? part of the regex is matching an optional sequence of smaller patterns. (\()? matches an optional ( and places it in Group 2. Then, (?(2)[0-9]{1,4}) matches 1 to 4 digits if Group 2 matched. Then (?(2)\)) matches ) if Group 2 matched. Basically, this is equal to (?:\([0-9]{1,4})\))?.
Thus, you need no conditional construct here.
You may use
^\+?(?:\([0-9]{1,4})\)?[0-9]{2}(?:[. -]?[0-9]{2}){4}$
See the regex demo
Details
^ - start of string\+? - an optional +(?:\([0-9]{1,4})\)? - an optional sequence: (, 1 to 4 digits and )[0-9]{2} - 2 digits(?:[. -]?[0-9]{2}){4} - 4 occurrences of an optional space, dot or - followed with 2 digits$ - end of string.