3v4l.org

run code in 300+ PHP versions simultaneously
<?php $array1 = array('A', 'B'); $array2 = array('1', '2', '3'); $num = count($array2); //The total number of possible combinations $total = pow(2, $num); //Loop through each possible combination for ($i = 0; $i < $total; $i++) { $ff=''; //For each combination check if each bit is set for ($j = 0; $j < $num; $j++) { //Is bit $j set in $i? if (pow(2, $j) & $i) $ff = $ff.''.$array2[$j]; } $temp[]=$ff; } print_r($temp);
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, 5.5.24 - 5.5.35, 5.6.8 - 5.6.21, 7.0.0 - 7.0.20, 7.1.0 - 7.1.25, 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 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
Array ( [0] => [1] => 1 [2] => 2 [3] => 12 [4] => 3 [5] => 13 [6] => 23 [7] => 123 )

preferences:
271.92 ms | 406 KiB | 327 Q