Question

Bear with me, as I’m quite new to using regular expressions.

I have regexp checks on three fields, as marked in my code below. No matter what I enter in the fields, neither my character length restrictions, nor my actual character restrictions are enforced; all of these fields seem to simply “skip over” my regular expression checks and validate as true.

// NAME
    if (preg_match('%^[A-Za-z\.\' \-]{12,80}$%', stripslashes($name)) === false) {
        $name = false;
        $errors[] = 'You need to enter a valid name. No slashes or quotes are allowed.';
    }
    else { echo 'Test: RegExp Validation passed for "NAME" <br />'; }

// PHONE NUMBER
    if (preg_match('%^([0-9]( |-)?)?(\(?[0-9]{3}\)?|[0-9]{3})( |-)?([0-9]{3}( |-)?[0-9]{4}|[a-zA-Z0-9]{7})$%', $phone) === false) {
        $phone = false;
        $errors[] = 'A valid phone number must be entered. Only numbers, dashes, and parentheses are allowed';
    }
    else { echo 'Test: RegExp Validation passed for "PHONE" <br />'; }

//EXTENSION
    if (!empty($phnext) && preg_match('%^[0-9]{3,5}$%', $phnext) === false) {
        $phnext = false;
        $errors[] = 'Only 3 to 5 numbers are allowed for the phone extension.';
    }
    else { echo 'Test: RegExp Validation passed for "EXTENSION" <br />'; }

I don’t get any syntax, compilation, or out-of-range errors. So I’m wondering, are my actual regexp strings wrong, or is my logic wrong somewhere? It wouldn’t be the first time. I’m just a little stumped.

Answer 1

preg_match will only return FALSE if an error occurred. In the case of no matches, it will return 0. You should not be using a strict test preg_match(...) === FALSE, instead you can use:

if (preg_match(...)) {
    // passed
} else {
    // didn't pass
}