Regex for Passport Number

Question

I am trying to implement regex validation for passport number.

My requirement is

1. Length should be minimum 3 characters to a maximum of 20 characters.
2. Should not be only 0's

I tried with the below regular expression

^(?!0{3,20})[a-zA-Z0-9]{3,20}$

This seems to work for most of the cases, but incase my text contains 3 or more leading zeros, it seems to fail. Such as '00000001'.

Example Matches

• 101AE24 - Working as expected
• 00 - Not working as expected
• 01234 - Working as expected
• 00001 - Not working (But it should also be match)

Any help would be much appreciated.

Solution 1

What about this?

^(?!^0+$)[a-zA-Z0-9]{3,20}$

Instead of saying 'reject values with 3-20 zeros', we can just say 'reject anything that only contains zeros (regardless of the length, since <3 and >20 fail anyway)

Solution 2

It took me around 5 minutes to learn Regex online [iOS, Swift]. Here is my a simple answer to understand for beginners.

For 1 Alphabet & 7 digits:

[A-Z]{1}[0-9]{7}

For 2 Alphabets & 7 digits:

[A-Z]{2}[0-9]{7}

--

func validatePassport(from value: String?) throws {
    guard let passportNo = value, !passportNo.isEmpty else {
        throw MyError.noPassport
    }
    let PASSPORT_REG_EX = "[A-Z]{1}[0-9]{7}"
    let passport = NSPredicate(format:"SELF MATCHES %@", PASSPORT_REG_EX)

    if !passport.evaluate(with: passportNo) {
        throw MyError.invalidPassport
    }
}