Online PHP editor | refs for a1fce

$keyword_1 = "keyword1"; $keyword_2 = "keyword2"; $keyword_2 = "keyword3"; $keyword_4 = "keyword4"; $keyword_5 = "keyword5"; $keyword_6 = "keyword6"; $keyword_7 = "keyword7"; $city_1 = "city1"; $city_2 = "city2"; $city_3 = "city3"; $city_4 = "city4"; $city_5 = "city5"; $city_6 = "city6"; $city_7 = "city7"; <?php function permutation(array $arr) { while($ele=array_shift($arr)) { $x=$ele; echo $x."\n"; foreach($arr as $rest) { $x.=" $rest"; echo $x."\n"; } } } permutation(array("one","two","three","four"));