Developer
<?php
namespace Faker\Calculator;
/**
* Utility class for generating and validating Luhn numbers.
*
* Luhn algorithm is used to validate credit card numbers, IMEI numbers, and
* National Provider Identifier numbers.
*
* @see http://en.wikipedia.org/wiki/Luhn_algorithm
*/
class Luhn
{
/**
* @return int
*/
private static function checksum(string $number)
{
$number = (string) $number;
$length = strlen($number);
$sum = 0;
for ($i = $length - 1; $i >= 0; $i -= 2) {
$sum += $number[$i];
}
for ($i = $length - 2; $i >= 0; $i -= 2) {
$sum += array_sum(str_split($number[$i] * 2));
}
return $sum % 10;
}
/**
* @return string
*/
public static function computeCheckDigit(string $partialNumber)
{
$checkDigit = self::checksum($partialNumber . '0');
if ($checkDigit === 0) {
return '0';
}
return (string) (10 - $checkDigit);
}
/**
* Checks whether a number (partial number + check digit) is Luhn compliant
*
* @return bool
*/
public static function isValid(string $number)
{
return self::checksum($number) === 0;
}
/**
* Generate a Luhn compliant number.
*
* @return string
*/
public static function generateLuhnNumber(string $partialValue)
{
if (!preg_match('/^\d+$/', $partialValue)) {
throw new \InvalidArgumentException('Argument should be an integer.');
}
return $partialValue . Luhn::computeCheckDigit($partialValue);
}
}
Developer
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