Online PHP editor | output for F8NNH

<?php $data = [ ['alteration1', 'alteration4',], ['alteration2','alteration3'], ['alteration2','alteration3'], [] ]; $combinations = [[]]; foreach($data as $index => $current_data){ $current_data = array_unique($current_data); $temp_combinations = []; foreach($current_data as $value){ foreach($combinations as $each_combination){ $temp_combinations[] = array_merge($each_combination,[$value]); } } $combinations = $temp_combinations; } $set = []; $unique_combinations = []; foreach($combinations as $each_combination){ natsort($each_combination); $serialized_form = implode(",",$each_combination); if(isset($set[$serialized_form])) continue; if(empty($each_combination)) continue; $unique_combinations[] = $each_combination; $set[$serialized_form] = true; } print_r($unique_combinations);