note 82257 added to function.array-diff-key

To return the unique elements (those with a key that exists only once in either array but not in both) try: function array_unique_diff ($array1, $array2) { array_merge(array_diff_key($array1, $array2), array_diff_key($array2, $array1)); } Example: $array1 = array('blue' => 1, 'red' => 2, 'green' => 3, 'purple' => 4); $array2 = array('green' => 5, 'blue' => 6, 'yellow' => 7, 'cyan' => 8); array_diff_key($array1, $array2) returns array ( 'red' => 2, 'purple' => 4 ) array_diff_key($array2, $array1) returns array ( 'yellow' => 7, 'cyan' => 8, ) array_unique_diff($array1, $array2); returns array ( 'red' => 2, 'purple' => 4, 'yellow' => 7, 'cyan' => 8, ) ---- Server IP: 208.69.120.35 Probable Submitter: 128.173.242.161 ---- Manual Page -- http://www.php.net/manual/en/function.array-diff-key.php Edit -- https://master.php.net/note/edit/82257 Del: integrated -- https://master.php.net/note/delete/82257/integrated Del: useless -- https://master.php.net/note/delete/82257/useless Del: bad code -- https://master.php.net/note/delete/82257/bad+code Del: spam -- https://master.php.net/note/delete/82257/spam Del: non-english -- https://master.php.net/note/delete/82257/non-english Del: in docs -- https://master.php.net/note/delete/82257/in+docs Del: other reasons-- https://master.php.net/note/delete/82257 Reject -- https://master.php.net/note/reject/82257 Search -- https://master.php.net/manage/user-notes.php