<?php
function GetLuhnCheckDigit($number) {
$sum = 0;
$alt = true;
$digits = str_split($number);
for ($i = count($digits) - 1; $i >= 0; $i--) {
$curDigit = $digits[$i];
if ($alt) {
$curDigit *= 2;
if ($curDigit > 9)
$curDigit -= 9;
}
$sum += $curDigit;
$alt = false;
}
if (($sum % 10) == 0 ){
return 0;
}
echo abs($sum) . PHP_EOL;
return (10 - (abs($sum) % 10));
}
echo GetLuhnCheckDigit(1234567891234567891);
- Output for 5.5.0 - 5.5.38, 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
- 92
8
preferences:
264.91 ms | 407 KiB | 326 Q