Online PHP editor | output for LdNlI

<?php $array1 = array('A', 'B'); $array2 = array('1', '2', '3'); $num = count($array2); $comb = array(); //The total number of possible combinations $total = pow(2, $num); //Loop through each possible combination for ($i = 0; $i < $total; $i++) { $flag = ''; //For each combination check if each bit is set for ($j = 0; $j < $num; $j++) { //Is bit $j set in $i? if (pow(2, $j) & $i) $flag = $flag.''.$array2[$j]; } if(!empty($flag)) $comb[] = $flag; } $result = array(); foreach($array1 as $val) { foreach($comb as $co) { $result[] = $val."".$co; } } print_r($result);