problem with preg_match

I have to validate for a Laser Credit card. The card starts with either 6304, 6706, 6709, 6771 and is 16 or 19 digits in length. I have a preg_match and I am passing in the card number starting with 6706 and has 19 digits but it returns false.

    // Laser (Laser) P: 6304, 6706, 6709, 6771 L: 16,19
    } elseif (preg_match('/^(?:[6304|6706|6709|6771])\d{12,15}$/', $number)) {
        $type = 'laser';
开发者_运维百科

---

/^6(?:304|706|709|771)(?:\d{12}|\d{15})$/

Broken down:

/^                        # start of line
   6(?:304|706|709|771)     # your 6xxx codes
   (?:\d{12}|\d{15})        # 12 (16-4) or 15 (19-4) more numbers
$/                        # end of pattern

To point out the mistakes you had:

(?:[6304|6706|6709|6771])

Remember that [] is a CLASS. That means to look for any of those characters within the brackets. If you're going for either/or, you need to use a group ().

Fixed it should look like: (?:6304|6706|6709|6771)

\d{12,15}

My understanding is you need fixed-length of numbers, not a variable one. Your quantifier is saying it can be 12, 13, ..., 15 more numbers. We only want 12 OR 15 more.