Regex pattern for mobile number validation with extension

Question

I have seperate regex validations for my requirement but struggling to combine them in one. I am validation mobile numbers with country code or starting with 00 and also if they contain extension number(2-5 digits) seperated by #

Following is the example of valid Number :

+919986040933
00919986040933
+919986040933#12
+919986040933#123
+919986040933#1234
+919986040933#12345

I have following regex to validate the above:

var phoneRegexWithPlus = "^((\\+)|(00))[0-9]{10,14}$";
var phoneRegexWithZero = "^((\\+)|(00))[0-9]{9,12}$";
var phoneRegexExtension = "^[0-9]{2,5}$";

Currently i am checking whether number contains #,if yes then split it and match number and extension part seperately where extension is comething after hash.

My problem is now that i have to create one regex combining the above three,can anyone help me with that as m not good in regex. Thanks in advance.

Answer 1

I suggest this expression:

^\+?(?:00)?\d{12}(?:#\d{2,5})?$

See the regex demo

Expression explanation:

• ^ - start of string
• \+? - an optional plus (as ? matches the + one or zero times)
• (?:00)? - an optional 00
• \d{12} - Exactly 12 digit string
• (?:#\d{2,5})? - an optional (again, ? matches one or zero times) sequence of:
  • # - a literal hash symbol
  • \d{2,5} - 2 to 5 digits (your phoneRegexExtension)
• $ - end of string.

The phoneRegexWithPlus and phoneRegexWithZero are covered with the first obligatory part \+?(?:00)?\d{12} that matches 12 to 14 digits with an optional plus symbol at the start.

NOTE: The regex is adjusted to the sample input you provided. If it is different, please adjust the limiting quantifiers {12} (that can be replaced with, say, {9,14} to match 9 to 14 occurrences of the quantified pattern).