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<?php
namespace IsoCodes;
/**
* Abstract Class Gtin Global Trade Item Numbers.
*
* @link http://www.gs1.org/how-calculate-check-digit-manually
*/
abstract class Gtin
{
* @param string $gtin
* @param int $length
* @return bool
public static function check($gtin, $length)
$gtin = self::unDecorate($gtin);
if (strlen($gtin) != $length) {
return false;
}
$expr = sprintf('/\\d{%d}/i', $length);
if (!preg_match($expr, $gtin)) {
$check = 0;
for ($i = 0; $i < $length; $i += 2) {
if ($length % 2 == 0) {
$check += 3 * substr($gtin, $i, 1);
$check += (int) substr($gtin, $i + 1, 1);
} else {
$check += (int) substr($gtin, $i, 1);
$check += 3 * substr($gtin, $i + 1, 1);
return $check % 10 == 0;
* @return string
public static function unDecorate($gtin)
// removing hyphens
$gtin = str_replace(' ', '', $gtin);
$gtin = str_replace('-', '', $gtin); // this is a dash
$gtin = str_replace('‐', '', $gtin); // this is an authentic hyphen
return $gtin;
ronanguilloux /
IsoCodes
