I have a problem with creating regexp to allow: exactly 2 letters at the beginning exactly 10 numbers after letters at most 4 "-" between numbers (should allow also without it) so example of valid string is GB123-55-22-22-6 , my current regexp is: /^([A-Z]{2})?[0-9]{10}$/ . He allow GB1235522226 but I have a problem with "-". can somoene tell me how to allow this regexp to use at most 4 "-" chars? thanks for any help!

Reputation: 179

Regexp to allow letters, numbers and -

I have a problem with creating regexp to allow:

so example of valid string is GB123-55-22-22-6,

my current regexp is: /^([A-Z]{2})?[0-9]{10}$/. He allow GB1235522226 but I have a problem with "-".

can somoene tell me how to allow this regexp to use at most 4 "-" chars?

thanks for any help!

Upvotes: 2

Reputation: 626748

You can use

^(?:[A-Z]{2})?(?=(?:-?\d){10}$)[0-9]+(?:-[0-9]+){0,4}$

Details:

^ - start of string
(?:[A-Z]{2})? - optional two letters
(?=(?:-?\d){10}$) - there must be 10 digits optionally separated with a - till end of string, the string must end with a digit
[0-9]+ - one or more digits
(?:-[0-9]+){0,4} - zero to four occurrences of a hyphen and then one or more digits
$ - end of string.

Upvotes: 1