--TEST-- Test array_intersect_key() function : usage variation - Passing Multi dimensional array --FILE-- array('blue' => 1, 'red' => 2), 'second' => array('yellow' => 7), 'third' => array(0 =>'zero'), ); $array2 = array ( 'first' => array('blue' => 1, 'red' => 2,), 'second' => array('cyan' => 8), 'fourth' => array(2 => 'two'), ); var_dump( array_intersect_key($array1, $array2) ); var_dump( array_intersect_key($array2,$array1 ) ); ?> ===DONE=== --EXPECTF-- *** Testing array_intersect_key() : usage variation *** array(2) { ["first"]=> array(2) { ["blue"]=> int(1) ["red"]=> int(2) } ["second"]=> array(1) { ["yellow"]=> int(7) } } array(2) { ["first"]=> array(2) { ["blue"]=> int(1) ["red"]=> int(2) } ["second"]=> array(1) { ["cyan"]=> int(8) } } ===DONE===