DragonBe\Vies\Validator\ValidatorHR::validate PHP Method

    public function validate($vatNumber)
    {
        if (strlen($vatNumber) != 11) {
            return false;
        }
        $product = 10;
        for ($i = 0; $i < 10; $i++) {
            $sum = ($vatNumber[$i] + $product) % 10;
            $sum = $sum == 0 ? 10 : $sum;
            $product = 2 * $sum % 11;
        }
        return ($product + (int) $vatNumber[10]) % 10 == 1 ? true : false;
    }