The array_diff_uassoc Function
The array_diff_uassoc function compares arrays and returns elements from the first array that are absent in subsequent arrays. In this case, key comparison is performed using a user-defined callback function.
Syntax
array_diff_uassoc(array $array1, array $array2, ..., callable $key_compare_func): array
Example
Let's compare two arrays with a user-defined function for key comparison:
<?php
function compareKeys($a, $b) {
if ($a === $b) return 0;
return ($a > $b) ? 1 : -1;
}
$array1 = ['a' => 1, 'b' => 2, 'c' => 3];
$array2 = ['a' => 1, 'b' => 5, 'd' => 4];
$res = array_diff_uassoc($array1, $array2, 'compareKeys');
print_r($res);
?>
Code execution result:
[
'b' => 2,
'c' => 3,
]
Example
Case-sensitive key comparison:
<?php
function caseSensitiveCompare($a, $b) {
return strcasecmp($a, $b);
}
$array1 = ['A' => 1, 'B' => 2, 'C' => 3];
$array2 = ['a' => 1, 'b' => 2, 'd' => 4];
$res = array_diff_uassoc($array1, $array2, 'caseSensitiveCompare');
print_r($res);
?>
Code execution result:
[
'C' => 3
]
See Also
-
the
array_difffunction,
which compares arrays by values -
the
array_diff_assocfunction,
which compares arrays by values and keys -
the
array_udiff_assocfunction,
which compares arrays with a callback function for values
