<?php
function generateEANdigit($code)
{
$weightflag = true;
$sum = 0;
for ($i = strlen($code) - 1; $i >= 0; $i--) { $sum += (int)$code[$i] * ($weightflag?3:1);
$weightflag = !$weightflag;
}
return (10 - ($sum % 10)) % 10;
}
echo generateEANdigit( 700299221111 );
PD9waHAKCmZ1bmN0aW9uIGdlbmVyYXRlRUFOZGlnaXQoJGNvZGUpCnsKICAkY29kZSA9IHN0cnZhbCgkY29kZSk7CiAgJHdlaWdodGZsYWcgPSB0cnVlOwogICRzdW0gPSAwOwogIGZvciAoJGkgPSBzdHJsZW4oJGNvZGUpIC0gMTsgJGkgPj0gMDsgJGktLSkgewogICAgJHN1bSArPSAoaW50KSRjb2RlWyRpXSAqICgkd2VpZ2h0ZmxhZz8zOjEpOwogICAgJHdlaWdodGZsYWcgPSAhJHdlaWdodGZsYWc7CiAgfQogIHJldHVybiAoMTAgLSAoJHN1bSAlIDEwKSkgJSAxMDsKfQoKZWNobyBnZW5lcmF0ZUVBTmRpZ2l0KCA3MDAyOTkyMjExMTEgKTs=