如何正确添加和OR语句

Question

I am trying to do a comparison of serial numbers like so 20140831-123 or 20140831-1234 so the form can accept our new serial numbers which contain 4 last numbers. So far I have tried an elseif statement and an or operator with no results what am I doing wrong? is there a way to change the reg expression itself to accept 3 or 4 digits at the end of the serial?

if($name == 'newserial1'){
        $newserial1 = $_POST['newserial1'];

        if($newserial1 != '') {
            if(!preg_match('/^([0-9]{8}-)([0-9]{3})$/', $newserial1) ||
             (!preg_match('/^([0-9]{8}-)([0-9]{4})$/', $newserial1))) {
                $result['valid'] = false;
                $result['reason'][$name] = 'Incorrect Serial Number.';
            }
        }
    }

Answer 1

Just use the below regex to match last 3 or 4 digits also,

^([0-9]{8}-)([0-9]{3,4})$

DEMO

Explanation:

• ^ Asserts that we are at the start.
• ([0-9]{8}-) Captures 8 digits and a following - symbol.
• ([0-9]{3,4}) Remaining three or four digits are captured by the second group.
• $ Asserts that we are at the end.