Ruby regex gsub any other characters except + on start (phone number)

Question

I am looking to remedy the following formats or invalid formats to a working phone number:

1 (639)-234-2323 => 6392342323
2 (042)-982-2234 => 0429822234
3 0974829-928  => 0974829928
4 +83246-983-34 => +832459834
5 +836(737)-898+78 => +83673789878

I am able to use this code and I can get my results right if a certain 1-4 are given, but if 5 , I am really going nuts.

row[1] = row[1].gsub('(','').gsub(')','').gsub('-','').gsub(' ','')

This sample is used in an import file. So you can't expect a prompt to a user.

I am also open to possibly importing record with invalid format, but should just be formatted into an accepted phone number (given parentheses inside anywhere or any + signs anywhere).

EDIT I want to have a solution to my 5 given example. Since I can't remove + signs anywhere without removing the first one.

EDIT 2 I asked again in the comment section that I need to include such phone format:

6 (+65)92349577 => +6592348577

@WiktorStribiżew suggested the following regex: s.gsub(/\\A\\(?(\\+)|\\D+/, '\\1') from his original answer (the accepted one)

Answer 1

The solution is to capture the first + and just match all other non-digit symbols:

s.gsub(/\A(\+)|\D+/, '\1')

See the regex demo

Pattern details :

• \\A(\\+) - a + (that is captured into a capturing group #1 since it is wrapped with capturing parentheses) at the beginning of the string ( \\A )
• | - or
• \\D+ - one or more characters other than a digit.

The \\1 in the replacement is a backreference to the contents stored in capturing group #1, it restores the initial + in the replacement result