array_udiff_uassoc()

array_udiff_uassoc() — Computes the difference of arrays with additional index check, compares data and indexes by a callback function.

Built-in function of PHP 8.5. The manual lists it as available in PHP 5, PHP 7, PHP 8. This page is the reference card: signature, parameters and return value, plus the changelog and the example the manual provides.

Signature

array_udiff_uassoc(array $array, array ...$arrays, callable $value_compare_func, callable $key_compare_func): array callback(mixed $a, mixed $b): int

Parameters

ParameterTypeWhat it takes
$arrayarrayThe first array.
...$arraysarrayArrays to compare against.
$value_compare_funccallableThe sorting callback must handle any value from any array in any order, regardless of the order they were originally provided. This is because each individual array is first sorted before being compared against other arrays. For example: <?php $arrayA = ["string", 1]; $arrayB = [["value" => 1]]; // $item1 and $item2 can be any of "string", 1 or ["value" => 1] $compareFunc = static function ($item1, $item2) { $value1 ...
$key_compare_funccallableThe comparison of keys (indices) is done also by the callback function key_compare_func. This behaviour is unlike what array_udiff_assoc() does, since the latter compares the indices by using an internal function.

Return value

Returns an array containing all the values from array that are not present in any of the other arguments.

Example

A runnable snippet:

class cr { private $priv_member; function __construct($val) { $this->priv_member = $val; } static function comp_func_cr($a, $b) { if ($a->priv_member === $b->priv_member) return 0; return ($a->priv_member > $b->priv_member)? 1:-1; } static function comp_func_key($a, $b) { if ($a === $b) return 0; return ($a > $b)? 1:-1; } } $a = array("0.1" => new cr(9), "0.5" => new cr(12), 0 => new cr(23), 1=> new cr(4), 2 => new cr(-15),); $b = array("0.2" => new cr(9), "0.5" => new cr(22), 0 => new cr(3), 1=> new cr(4), 2 => new cr(-15),); $result = array_udiff_uassoc($a, $b, array("cr", "comp_func_cr"), array("cr", "comp_func_key")); print_r($result);

Output:

Array ( [0.1] => cr Object ( [priv_member:cr:private] => 9 ) [0.5] => cr Object ( [priv_member:cr:private] => 12 ) [0] => cr Object ( [priv_member:cr:private] => 23 ) )

See also

array_diff(), array_diff_assoc(), array_udiff(), array_udiff_assoc(), array_intersect(), array_intersect_assoc(), array_uintersect(), array_uintersect_assoc(), array_uintersect_uassoc()

All PHP 8.5 built-in functions

Reference card built from the PHP manual page array_udiff_uassoc() (PHP documentation, CC BY 3.0). The page is generated from the manual, so the wording of the parameter and return value text follows php.net.