Test project for media files management.
<?php
namespace Faker\Calculator;
/**
* Utility class for validating EAN-8 and EAN-13 numbers
*/
class Ean
{
/**
* @var string EAN validation pattern
*/
public const PATTERN = '/^(?:\d{8}|\d{13})$/';
/**
* Computes the checksum of an EAN number.
*
* @see https://en.wikipedia.org/wiki/International_Article_Number
*
* @return int
*/
public static function checksum(string $digits)
{
$sequence = (strlen($digits) + 1) === 8 ? [3, 1] : [1, 3];
$sums = 0;
foreach (str_split($digits) as $n => $digit) {
$sums += ((int) $digit) * $sequence[$n % 2];
}
return (10 - $sums % 10) % 10;
}
/**
* Checks whether the provided number is an EAN compliant number and that
* the checksum is correct.
*
* @param string $ean An EAN number
*
* @return bool
*/
public static function isValid(string $ean)
{
if (!preg_match(self::PATTERN, $ean)) {
return false;
}
return self::checksum(substr($ean, 0, -1)) === (int) substr($ean, -1);
}
}