[RFC] array_only() and array_except() – Utility functions for array key filtering

It seems clear to me that this proposal was under-researched because the
RFC doesn't even acknowledge the fact that PHP already has native functions
which serve the exact same purpose (and they have more indicative names).

I'm not a voter, but I would vote No on this one because the new functions
aren't adding significant value to the language.

Mick

Hi,

Thanks for the feedback.

1. Yes, *array_intersect_key() *and *array_diff_key() *can be used today,
   but the RFC proposes dedicated functions for better readability, less
   boilerplate, and potentially better performance and lower memory usage by
   avoiding temporary arrays.

2. Good point about naming. Making the key-filtering behavior explicit
   (e.g., array_only_keys and array_except_keys) improves clarity and
   avoids confusion.

Le 20 févr. 2026 à 10:25, Muhammed Arshid KV arshidkv12@gmail.com a
écrit :

Hello Internals,

I would like to propose a new RFC titled array_only() and array_except()
.

RFC: https://wiki.php.net/rfc/array_only_except
https://wiki.php.net/rfc/array_only_except?utm_source=chatgpt.com

This RFC proposes adding two utility functions to the PHP core:

• array_only(array $array, array $keys): array
• array_except(array $array, array $keys): array

These functions allow selecting or excluding specific keys from an array.

Similar helpers are commonly used in frameworks, and adding native support
would improve readability and consistency in userland code.

Summary:

• array_only() returns a new array containing only the specified keys.
• array_except() returns a new array excluding the specified keys.
• Original array is not modified.
• Works with associative and numeric keys.
• No impact on SAPIs or on OPcache.

I would appreciate feedback and suggestions from the community.
If there is general agreement, I plan to move the RFC forward.

Thanks,
Muhammed Arshid KV

Hi,

The principle of the RFC is interesting to me, as it is a situation I
encounter from time to time. Two remarks:

1. It may be interesting to compare with currently available solutions.
   Currently, I use array_intersect_key and array_diff_key when I need
   the semantics of proposed array_only and array_except:

array_intersect_key($data, ['id' => null, 'email' => null]);

2. I think that the name of the new functions ought to make evident that
   we are filtering on keys and not on something else. I suggest:
   array_only_keys and array_except_keys.

—Claude