Regex to extend ISBN-10 and ISBN-13 to non-English speaking countries

Question

I am looking for a Regex to match a string which should:

• start with an optional 978- or 979- prefix
• continue with a digit
• have a permutation of exactly 7 digits and 2 hyphens, without 2 consecutive hyphens
• end with a sequence of digit, hyphen, digit (which can be an x)

NB.: Hyphens can be replaced (coherently) by spaces or not present altogether...

Match:

• 9780309091695
• 0309091695
• 979030909169x
• 030909169x
• 978-0-309-09169-5
• 1-84356-028-3
• 978 0 8044 2957 7
• 93 86954 21 4
• 979-0-943396-04-2
• 0-9752298-0-X
• 979 99921 58 10 0
• 80 902734 1 x
• 979-9971-5-0210-X
• 978-425-059-0
• 979 85 359 0277 x

No Match:

• 978030909169
• 97803090916951
• 030909169
• 03090916951
• 978-0--30909169-5
• 978 0 30909169 5
• 978 0-309 09169-5
• 978-0-309-091695-
• -1-84356-028-3
• 978-0309091695
• 978-0-30909169-5
• 1-843-56-028-3

My current proposition is thanks to answers I had to a previous question and should be able to be further simplified: /^((97(8|9))*d{9}|(97(8|9)-)*(?=.{11}-)(?:d+-){3}|(97(8|9) )*(?=.{11} )(?:d+ ){3})[dx]$/i

question from:https://stackoverflow.com/questions/65925071/regex-to-extend-isbn-10-and-isbn-13-to-non-english-speaking-countries

Answer 1

You may try:

^(?![- ])(?:(?:97[89])?([- ]?)(?=(?:d1?){9}1[dxX]$)(?:d+1){3}[dxX]|(?=.{11}([- ])[dxX]$)(?:d+2){3}[dxX])

See the online demo

• ^ - Start string anchor.
• (?![- ]) - Negative lookahead to prevent a leading hyphen or space.
• (?: - Open non-capture group:
  • (?: - Open non-capture group:
    • 97[89] - Match "97" followed by either an 8 or 9.
    • )? - Close non-capture group and make it optional.
  • ( - Open 1st capture group:
    • [- ]? - Optionally match an hyphen or space.
    • ) - Close 1st capture group.
  • (?= - Open positive lookahead:
    • (?: - Open non-capture group:
      • d1? - Capture a digit and optionally match what is captured in the 1st capture group.
      • ){9} - Close the non-capture group and match it nine times (to assert a position with 9 digits ahead).
    • 1[dxX]$ - Again match what is captured in the 1st capture group followed by a digit or lower- or uppercase "x" and the end string anchor.
    • ) - Close positive lookahead.
  • (?: - Open non-capture group:
    • d+1 - 1+ digits followed by what is captured in the 1st capture group.
    • ){3} - Close the non-capture group and match it three times.
  • [dxX] - Match a digit, a lower- or uppercase "x".
  • | - Or:
  • (?= - Open positive lookahead:
    • .{11} - Match eleven characters other than newline.
    • ([- ]) - OA 2nd capture group to match either hypen or space.
    • [dxX]$ - Match a digit, a lower- or uppercase "x" up to end string anchor.
    • ) - Close positive lookahead.
  • (?: - Open non-capture group:
    • d+2 - Match 1+ digits and what is captured in the 2nd capture group.
    • ){3} - Close non-capture group and match three times.
  • [dxX]$ - Match a digit, a lower- or uppercase "x".
  • ) - Close non-capture group.