array_diff_ukey

Description

array_diff_ukey() returns an array containing all the values of array1 that have keys that are not present in any of the other arguments. Note that the associativity is preserved. This function is like array_diff() except the comparison is done on the keys instead of the values.

This comparison is done by a user supplied callback function. It must return an integer less than, equal to, or greater than zero if the first key is considered to be respectively less than, equal to, or greater than the second.

Example 1. array_diff_ukey() example <?php function 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) }

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() and array_intersect_ukey().