    public function getSigFigs($n) {
        $n = ltrim($n, '0+-');
        $dp = strpos($n, '.'); // decimal position
        if ($dp === false) {
            $sigfigs = strlen(rtrim($n, '0'));
        } else {
            $sigfigs = strlen(ltrim($n, '0.')); // eliminate extra decimal character
            if ($dp !== 0) $sigfigs--;
        }
        return $sigfigs;
    }
The software does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.