Regular Expression to reformat a US phone number in Javascript

Question

I\'m looking to reformat (replace, not validate - there are many references for validating) a phone number for display in Javascript. Here\'s an example of some of the data:

Answer 1

For US Phone Numbers

/^\(?(\d{3})\)?[- ]?(\d{3})[- ]?(\d{4})$/

Let’s divide this regular expression in smaller fragments to make is easy to understand.

• /^\(?: Means that the phone number may begin with an optional (.
• (\d{3}): After the optional ( there must be 3 numeric digits. If the phone number does not have a (, it must start with 3 digits. E.g. (308 or 308.
• \)?: Means that the phone number can have an optional ) after first 3 digits.
• [- ]?: Next the phone number can have an optional hyphen (-) after ) if present or after first 3 digits.
• (\d{3}): Then there must be 3 more numeric digits. E.g (308)-135 or 308-135 or 308135
• [- ]?: After the second set of 3 digits the phone number can have another optional hyphen (-). E.g (308)-135- or 308-135- or 308135-

• (\d{4})$/: Finally, the phone number must end with four digits. E.g (308)-135-7895 or 308-135-7895 or 308135-7895 or 3081357895.

  Reference :

http://www.zparacha.com/phone_number_regex/