The example #1 can be modified (PHP 7 or higher) by using Spaceship operator (<=>):
<?php
//…
static function comp_func_cr($a, $b)
{
return $a->priv_member <=> $b->priv_member;
}
//…
?>
array_udiff_assoc
(PHP 5, PHP 7, PHP 8)
array_udiff_assoc — Computes the difference of arrays with additional index check, compares data by a callback function
Description
Computes the difference of arrays with additional index check, compares data by a callback function.
Note: Please note that this function only checks one dimension of a n-dimensional array. Of course you can check deeper dimensions by using, for example,
array_udiff_assoc($array1[0], $array2[0], "some_comparison_func");.
Parameters
-
array -
The first array.
-
arrays -
Arrays to compare against.
-
value_compare_func -
The comparison 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.
CautionReturning non-integer values from the comparison function, such as float, will result in an internal cast to int of the callback's return value. So values such as
0.99and0.1will both be cast to an integer value of0, which will compare such values as equal.CautionThe 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) {
$value1 = is_string($item1) ? strlen($item1) : (is_array($item1) ? $item1["value"] : $item1);
$value2 = is_string($item2) ? strlen($item2) : (is_array($item2) ? $item2["value"] : $item2);
return $value1 <=> $value2;
};
?>
Return Values
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.
Examples
Example #1 array_udiff_assoc() example
<?php
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);
?>The above example will output:
Array
(
[0.1] => cr Object
(
[priv_member:private] => 9
)
[0.5] => cr Object
(
[priv_member:private] => 12
)
[0] => cr Object
(
[priv_member:private] => 23
)
)
In our example above you see the "1" => new cr(4)
pair is present in both arrays and thus it is not in the output from the
function.
See Also
- array_diff() - Computes the difference of arrays
- array_diff_assoc() - Computes the difference of arrays with additional index check
- array_diff_uassoc() - Computes the difference of arrays with additional index check which is performed by a user supplied callback function
- array_udiff() - Computes the difference of arrays by using a callback function for data comparison
- array_udiff_uassoc() - Computes the difference of arrays with additional index check, compares data and indexes by a callback function
- array_intersect() - Computes the intersection of arrays
- array_intersect_assoc() - Computes the intersection of arrays with additional index check
- array_uintersect() - Computes the intersection of arrays, compares data by a callback function
- array_uintersect_assoc() - Computes the intersection of arrays with additional index check, compares data by a callback function
- array_uintersect_uassoc() - Computes the intersection of arrays with additional index check, compares data and indexes by separate callback functions
add a note
User Contributed Notes 2 notes
m dot ario dot huq at gmail dot com ¶
6 years ago
tmquang6805 at yahoo dot com ¶
10 years ago
Difference between array_udiff_assoc() and array_diff_assoc()
- array_udiff_assoc(): Compares the DATA with the user supplied callback function
- array_diff_assoc(): Compares the INDEX with the user supplied callback function
