Computes the difference of arrays using a callback function on the keys for comparison array_diff_uassoc array_diff Array Functions PHP Manual array_diff_ukey (PHP 5 >= 5.1.0)array_diff_ukey — Computes the difference of arrays using a callback function on the keys for comparison Description array array_diff_ukey ( array $array1 , array $array2 [, array $ ... ], callback $key_compare_func ) Compares the keys from array1 against the keys from array2 and returns the difference. This function is like array_diff() except the comparison is done on the keys instead of the values. Unlike array_diff_key() an user supplied callback function is used for the indices comparision, not internal function. Parameters array1 The array to compare from array2 An array to compare against ... More arrays to compare against key_compare_func callback function to use. The callback function must return an integer less than, equal to, or greater than zero if the first argument is considered to be respectively less than, equal to, or greater than the second. Return Values Returns an array containing all the entries from array1 that are not present in any of the other arrays. Examples Example #1 array_diff_ukey() example <?phpfunction key_compare_func($key1, $key2){ if ($key1 == $key2) return 0; else if ($key1 > $key2) return 1; else return -1;}$array1 = array('blue' => 1, 'red' => 2, 'green' => 3, 'purple' => 4);$array2 = array('green' => 5, 'blue' => 6, 'yellow' => 7, 'cyan' => 8);var_dump(array_diff_ukey($array1, $array2, 'key_compare_func'));?> The above example will output: array(2) { ["red"]=> int(2) ["purple"]=> int(4) } Notes Note: This function only checks one dimension of a n-dimensional array. Of course you can check deeper dimensions by using array_diff_ukey($array1[0], $array2[0], 'callback_func');. See Also array_diff() array_udiff() array_diff_assoc() array_diff_uassoc() array_udiff_assoc() array_udiff_uassoc() array_diff_key() array_intersect() array_intersect_assoc() array_intersect_uassoc() array_intersect_key() array_intersect_ukey() array_diff_uassoc array_diff Array Functions PHP Manual
