The array_diff_ukey function compares array keys, with an additional user-made function check, and returns the differences.
Syntax
array_diff_ukey(arr1, arr2, arr3, arr4, …, compare_func)
Parameters
arr1 − Array to compare from. Required.
arr2 − Array to compare against. Required.
arr3 − You can add more arrays to compare. Optional.
arr4 − You can add more arrays to compare. Optional.
compare_func − This callback function must return an integer <, =, or > than 0 if the first argument is considered to be respectively <, =, or > than the second.
Return
The array_diff_ukey() function returns an array containing the entries from the first array that are not present in any of the other arrays.
The following is an example that compare keys of the both the arrays.
Example
<?php
function compare_func($a, $b) {
if ($a === $b) {
return 0;
}
return ($a > $b)? 1:-1;
}
$arr1 = array("a" => "laptop", "b" => "keyboard", "c" => "mouse");
$arr2 = array("a" => "laptop", "d" => "mouse");
$res = array_diff_ukey($arr1, $arr2, "compare_func");
print_r($res);
?>Output
Array ( [b] => keyboard [c] => mouse )