Keskustelu: Koodit: PHP: ISBN-koodin tarkistus

<?php
$isbn = "951826184"; //ISBN-numero ilman tarkistusmerkkiä (MSCD Training Kit Microsoft Visual C++ 6.0, Edita 2000)
for ($i = 0; $i < 10; $i++) {
    $x = $i + 1;
    $temp[$i] = substr($isbn, $i, 1) * $x;
}
for ($i = 0; $i < 10; $i++) {
    $temp2 = $temp2 + $temp[$i];
}
if (gmp_mod($temp2, 11) == 10) {
    $check = "X";
} else {
    $check = gmp_mod($temp2, 11);
}
print "ISBN: " .substr($isbn, 0, 3) ."-" .substr($isbn, 3, 3) ."-" .substr($isbn, 6, 3) ."-" .$check;
?>