| private validateNational ( $vatNumber ) : string | ||
| $vatNumber | ||
| return | string | |
private function validateNational($vatNumber)
{
$checkval = 0;
for ($i = 2; $i <= 8; $i++) {
$checkval += $this->crossSum((int) $vatNumber[9 - $i] * ($this->isEven($i) ? 2 : 1));
}
$checkval = 10 - $checkval % 10;
return $checkval % 10;
}