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
(PHP 5, PHP 7)
array_udiff_assoc — Computes the difference of arrays with additional index check, compares data by a callback function
$array1
, array $array2
[, array $...
], callable $value_compare_func
) : arrayComputes the difference of arrays with additional index check, compares data by a callback function.
Informacja: Please note that this function only checks one dimension of a n-dimensional array. Of course you can check deeper dimensions by using, for example, array_udiff_assoc($array1[0], $array2[0], "some_comparison_func");.
array1
The first array.
array2
The second array.
value_compare_func
Funkcja porównująca musi zwrócić liczbę całkowitą mniejszą, równą lub większą od zera jeśli pierwszy argument jest uważany za odpowiednio mniejszy, równy lub większy od drugiego. Przed PHP 7.0.0 ta liczba musiała być z zakresu -2147483648 do 2147483647.
array_udiff_assoc() returns an array
containing all the values from array1
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.
Przykład #1 array_udiff_assoc() example
<?php
class cr {
private $priv_member;
function cr($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);
?>
Powyższy przykład wyświetli:
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.
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
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;
}
//…
?>