PHP: Test a Password Strength

PHP: Test a Password Strength

function PasswordStrength($password, $return_as_number = true) {
    if (strlen($password) == 0) {
        return 1;
    }

    $strength = 0;

    /* Get the length of the password */
    $length = strlen($password);

    /* Check if password is not all lower case */
    if (strtolower($password) != $password) {
        $strength += 1;
    }

    /* Check if password is not all upper case */
    if (strtoupper($password) == $password) {
        $strength += 1;
    }

    /* Check string length is 8-15 chars */
    if ($length >= 8 && $length <= 15) {
        $strength += 1;
    }

    /* Check if lenth is 16 - 35 chars */
    if ($length >= 16 && $length <= 35) {
        $strength += 2;
    }

    /* Check if length >35 chars */
    if ($length > 35) {
        $strength += 3;
    }

    /* Get the numbers in the password */
    preg_match_all('/[0-9]/', $password, $numbers);
    $strength += count($numbers[0]);

    /* Check for special chars */
    preg_match_all('/[|!@#$%&*\/=?,;.:\-_+~^\\\]/', $password, $specialchars);
    $strength += sizeof($specialchars[0]);

    /* Get the number of unique chars */
    $chars = str_split($password);
    $num_unique_chars = sizeof(array_unique($chars));
    $strength += $num_unique_chars * 2;

    /* Strength is a number 1-10 */
    $strength = $strength > 99 ? 99 : $strength;
    $strength = floor($strength / 10 + 1);

    /* Return number OR word */
    if ($return_as_number) {
        return $strength;
    } else {
        if (($strength >= 1) && ($strength < 3))
            return 'Weak';
        if (($strength >= 3) && ($strength < 6))
            return 'Normal';
        if (($strength >= 6) && ($strength < 8))
            return 'Good';
        if (($strength >= 8) && ($strength <= 10))
            return 'Awesome';
    }
}