WebCodeDoc

PHP array_intersect_ukey() Function

Quick summary: The PHP array_intersect_ukey() function computes the intersection of arrays using a user-defined callback to compare keys.

PHP array_intersect_ukey() Syntax 

array_intersect_ukey(array $array, array ...$arrays, callable $key_compare_func): array
PHP

PHP array_intersect_ukey() Basic examples 

$a = ['a'=>1,'b'=>2];
$b = ['A'=>9];
$result = array_intersect_ukey($a, $b, 'strcasecmp');
print_r($result);
PHP
Output:
Array ( [a] => 1 )

Performs case-insensitive key comparison.

PHP array_intersect_ukey() Real-world usage

PHP array_intersect_ukey() Edge cases 

array_intersect_ukey($a, $b, 'not_existing_function');
PHP
Output:
Warning

Callback must exist and be callable.

PHP array_intersect_ukey() Common mistakes

Confusing with array_intersect_uassoc()

array_intersect_ukey() compares keys only.

Incorrect
array_intersect_ukey(['a'=>1], ['a'=>2], 'strcmp');
Correct
array_intersect_uassoc(['a'=>1], ['a'=>2], 'strcmp');

Use array_intersect_uassoc() if values must also match.

PHP array_intersect_ukey() Frequently Asked Questions

What does array_intersect_ukey() do?

Intersection using user-defined key comparison.

Use case?

Custom key matching.

Callback required?

Yes.

Ignores values?

Yes.

Common mistake?

Wrong callback logic.

Return type?

Array.

Performance?

Moderate.

Safe?

Yes.

Alternative?

array_intersect_key().

Flexible?

Yes.

Best practice?

Optimize callbacks.

Used in advanced filtering?

Yes.

PHP array_intersect_ukey() Related PHP Functions