3v4l.org

run code in 300+ PHP versions simultaneously
<?php $code = "03255000000"; $len = strlen($code); $i = 0; $r = 1; $sum = 0; do { $r = ($i+1); $sum += ($code[$i]*$r); echo $code[$i]." * $r = $sum\n"; $i++; }while($i < $len); echo (string)($sum%11); ?>
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.0 - 5.5.35, 5.6.0 - 5.6.28, 7.0.0 - 7.0.20, 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
0 * 1 = 0 3 * 2 = 6 2 * 3 = 12 5 * 4 = 32 5 * 5 = 57 0 * 6 = 57 0 * 7 = 57 0 * 8 = 57 0 * 9 = 57 0 * 10 = 57 0 * 11 = 57 2

preferences:
257.17 ms | 406 KiB | 382 Q