Regex (JavaScript): match feet and/or inches

Question

I\'m trying to match feet and inches but I can\'t manage to get \"and/or\" so if first half is correct it validates:

Code: (in javascript)

Answer 1

Remove the + at the end (which allows more than one instance of feet/inches right now) and check for an empty string or illegal entries like 1'2 using a separate negative lookahead assertion. I've also changed the regex so group 1 contains the feet and group 2 contains the inches (if matched):

^(?!$|.*\'[^\x22]+$)(?:([0-9]+)\')?(?:([0-9]+)\x22?)?$

Test it live on regex101.com.

Explanation:

^          # Start of string
(?!        # Assert that the following can't match here:
 $         # the end of string marker (excluding empty strings from match)
|          # or
 .*\'      # any string that contains a '
 [^\x22]+  # if anything follows that doesn't include a "
 $         # until the end of the string (excluding invalid input like 1'2)
)          # End of lookahead assertion
(?:        # Start of non-capturing group:
 ([0-9]+)  # Match an integer, capture it in group 1
 \'        # Match a ' (mandatory)
)?         # Make the entire group optional
(?:        # Start of non-capturing group:
 ([0-9]+)  # Match an integer, capture it in group 2
 \x22?     # Match a " (optional)
)?         # Make the entire group optional
$          # End of string