array_udiff_assoc()
array_udiff_assoc() — Computes the difference of arrays with additional index check, compares data 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_assoc(array $array, array ...$arrays, callable $value_compare_func): array callback(mixed $a, mixed $b): int
Parameters
| Parameter | Type | What it takes |
|---|---|---|
| $array | array | The first array. |
| ...$arrays | array | Arrays to compare against. |
| $value_compare_func | callable | The 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 ... |
Return value
array_udiff_assoc() returns an array containing all the values from array that are not present in any of the other arguments. Note that the keys are used in the comparison unlike array_diff() and array_udiff(). The comparison of arrays' data is performed by using an user-supplied callback. In this aspect the behaviour is opposite to the behaviour of array_diff_assoc() which uses internal function for comparison.
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; } } $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),); $result = array_udiff_assoc($a, $b, array("cr", "comp_func_cr")); print_r($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_diff_uassoc(), array_udiff(), array_udiff_uassoc(), 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_assoc() (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.