3v4l.org

run code in 300+ PHP versions simultaneously
<?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=>[] ];*/ $result = array_shift($array); foreach ($array as $rows) { foreach ($rows as $k => $row) { $result[$k] = array_values(array_intersect($result[$k], $row)); } } echo '<pre>'; print_r($result); echo '</pre>';

preferences:
83.7 ms | 407 KiB | 5 Q