Online PHP editor | output for 9Drtq

<?php $array = [ 'visitPoints'=>[ 20=>[2,5,6,8,10,11], 35=>[2,5,6], 57=>[1] ], 'islands'=>[ 20=>[5,10,11], 35=>[5,6] ], 'animals'=>[ 20=>[5,11], 35=>[] ] ]; /*$result = [ 20=>[5,11], 35=>[], 57=>[], ];*/ $result = array_shift($array) ?? []; foreach ($array as $rows) { foreach ($result as $k => $row) { $result[$k] = array_values(array_intersect($row, $rows[$k] ?? [])); } } var_export($result);