PHP array_udiff_assoc() Function
Quick summary: The PHP array_udiff_assoc() function computes the difference of arrays using a user-defined callback for value comparison and also checks keys.
PHP array_udiff_assoc() Syntax
array_udiff_assoc(array $array, array ...$arrays, callable $value_compare_func): arrayPHP
PHP array_udiff_assoc() Basic examples
function cmp($a,$b){ return $a <=> $b; }
$a=['a'=>1,'b'=>2];
$b=['a'=>2];
print_r(array_udiff_assoc($a,$b,'cmp'));PHP
Output:
Array ( [a] => 1 [b] => 2 )Compares both keys and values, using callback for values.
PHP array_udiff_assoc() Real-world usage
PHP array_udiff_assoc() Edge cases
PHP array_udiff_assoc() Common mistakes
Confusing with array_udiff()
array_udiff_assoc() also checks keys.
Incorrect
array_udiff($a,$b,'cmp');Correct
array_udiff_assoc($a,$b,'cmp');Use correct function when keys matter.
PHP array_udiff_assoc() Frequently Asked Questions
What does array_udiff_assoc() do?
Computes array difference with user-defined value comparison and index check.
Use case?
Strict diff with custom comparison.
Callback required?
Yes.
Common mistake?
Ignoring key comparison.
Return type?
Array.
Performance?
Moderate.
Safe?
Yes.
Alternative?
array_diff_assoc().
Handles keys?
Yes.
Flexible comparison?
Yes.
Best practice?
Use for strict matching.
Used in configs?
Yes.