Question

I need help with a line of regular expression which validates phone number and it goes like this:
tel:/^(?:(?:\+?1\s*(?:[\.\-]\s*)?)?(?:\(\s*([2-9]1[02-9]|[2-9][02-8]1|[2-9][02-8][02-9])\s*\)|([2-9]1[02-9]|[2-9][02-8]1|[2-9][02-8][02-9]))\s*(?:[\.\-]\s*)?)?([2-9]1[02-9]|[2-9][02-9]1|[2-9][02-9]{2})\s*(?:[\.\-]\s*)?([0-9]{4})(?:\s*(?:#|x\.?|ext\.?|extension)\s*(\d+))?$/

And these are the formats it validates:

555 5555
1-555-555-5555
1.555.555.5555
15555555555 extension 555
15555555555 ext. 555
15555555555 # 555
15555555555 x. 555

I want to validate numbers like:

[phone]
773456284
0773456284

mostly international numbers

Answer 1

For a start, split that big chunk of regex. You might want to use your language’s verbose option if it has one. I split most of for you:

Telephone Numbers (should be 'orred'):
  \+?\d{3}(?:\ \d{3,4})+
  \d[-.]\d{3}[-.]\d{3}[-.]\d{4}
  \d{9,11}

Extensions (should be 'anded' with the previous regexes)
  (\ ext(?:\.|ension)(?:\ \#)?\ \d{3,4})?