Online PHP editor | refs for jYsEi

<?php $payload = ['A', 'B', 'C', 'D']; $total = (1 << count($payload)) - 1; $result = []; for($i = 1; $i <= $total; ++$i){ if(($i & ($i - 1)) == 0) continue; // avoiding single items since you don't wish to have them $curr = []; for($j = 0; $j < count($payload); ++$j){ if(($i & (1 << $j)) > 0){ $curr[] = $payload[ $j ]; } } $result[] = $curr; } usort($result, function($a, $b){ return strcmp( implode("|", $a), implode("|", $b) ); }); print_r($result);