Online PHP editor | output for j8U4n

<?php class NIP { private const WEIGHTS = [6, 5, 7, 2, 3, 4, 5, 6, 7]; private const NIP_MODULO = 11; private const INVALID_CHECKSUM = 10; public static function validate(string $nip): bool { $value = preg_replace('/[\s-]/', '', $nip); if ('0000000000' === $value || !preg_match('/^\d{10}$/', $value)) { return false; } $checkSum = self::getChecksum($value); if (self::INVALID_CHECKSUM === $checkSum || $checkSum !== ((int) (substr($value, -1)))) { return false; } return true; } private static function getChecksum(string $nip): int { $sum = 0; foreach (self::WEIGHTS as $key => $weight) { $sum += $weight * ((int) $nip[$key]); } return $sum % self::NIP_MODULO; } } $nip_numbers = array( "1234563218", "9876543290", "5627384901", "9012345678", "6748392105", "4382905671", "7591234890", "8901234765", "3210987654", "9876504321" ); $c = new NIP(); foreach ($nip_numbers as $a) { var_dump($c->validate($a)); }