requirments:

• min 5, max 50 symbols
• only uppercase letters and 0-9
• . / - space no more that 1 in a row
• can not start and end with this special symbols

Already got \A[A-Z0-9] (?:[.\/ -][A-Z0-9] )*\z. It works fine but does not validate string length. How to add min-max length validation?

CodePudding user response：

You can add a look-ahead at the start of the pattern to "scan" the total string length, before performing the other pattern checks. To match strings of a min-length 5 and max-length 50, add this to the start of the pattern:

(?=.{5,50}\z)