Add PHP 8.5 compat array functions: `array_first` and `array_last`

[TobiasBg]

PHP 8.5, expected to be released on November 20, 2025, thus shortly before WP 6.9, will bring two new array functions: array_first and array_last.

See ​https://wiki.php.net/rfc/array_first_last

Following up on [59783] (for #62558), [57337], and [52038], we should include polyfills in Core, to make developer adoption easier. For more reasoning, see ticket:62558#comment:6 .

Further details as well as possible polyfills are available at ​https://php.watch/versions/8.5/array_first-array_last and in the ​polyfills/array-first-array-last package.

[tusharbharti]

Hi, I am interested in creating a compat for array_first and array_last but would like to confirm how the function should handle following cases:

• If the values passed to the parameters are empty-ish like null, 0 , false etc, should the function return null ( by allowing empty-ish value to be passed ) or throw error when trying to access the key for these.

• If any error occurs while trying to get the first/last key of the array or trying to get the value from the array, should the function handle these errors or this is left for consumers to handle.

[peterwilsoncc]

@tusharbharti Thank you, that would be very helpful.

If the values passed to the parameters are empty-ish like null, 0 , false etc, should the function return null ( by allowing empty-ish value to be passed ) or throw error when trying to access the key for these.

In PHP the new functions are type strict so the compatibility implementations should be too. If you define the functions as function array_*( array $array ) then that will trigger the fatal error.

If any error occurs while trying to get the first/last key of the array or trying to get the value from the array, should the function handle these errors or this is left for consumers to handle.

Being type strict, this should be a use case that needs to be covered.

[tusharbharti]

Oh, got it! I will then start implementing the compat.

Add polyfills for array_first() and array_last(), planned for PHP 8.5. These provide a safe, side-effect-free way to fetch the first and last values of an array. This forward-compatibility makes it easier for Core, plugins, and themes to adopt upcoming PHP features while maintaining support for older versions.

The PR includes the polyfills for both functions in compat.php as well as unit tests.

Trac ticket: https://core.trac.wordpress.org/ticket/63853

Hi, I have a question ( not related to ticket but related to tests). Is there a guidelines on how tests comments are to be written as when I checked the tests files for PHPUnit, some files have comments as well as ticket mentioned but others either don't have any comments nor the tickets.

Here's the PHP implementation for reference: ​https://github.com/php/php-src/blob/0bf295944df7171acf47502d31dd7df8b9155d81/ext/standard/array.c#L4528-L4552

Is there a guidelines on how tests comments are to be written

It's a bit of mixed bag but something contributors are working toward improving. It's become relatively common for contribuitors to use the order listed in the description of this trac ticket.

It's a bit of mixed bag but something contributors are working toward improving. It's become relatively common for contribuitors to use the order listed in the description of this trac ticket.

Oh, got it! 👍, I will follow this format from now on.
Is there anything else that I need to implement from my side on this?

[mukesh27]

Mark ready for commit

[jorbin]

Self assigning for final review

[jorbin]

In 60672:

General: Add polyfills for new PHP 8.5 array functions: array_first and array_last.

This power couple of function is coming in PHP 8.5: array_first and array_last.

For more information on these functions, check out the PHP RFC at ​https://wiki.php.net/rfc/array_first_last.

Props tusharbharti, jorbin, peterwilsoncc, mukesh27, johnbillion.
Fixes #63853. See #63061.

[Soean]

In array_first() we could use

return $array[ array_key_first( $array ) ]; 

instead of

 foreach ( $array as $value ) { return $value; } 

[TobiasBg]

@Soean: I think this was a deliberate choice to save a function call, see ​https://github.com/WordPress/wordpress-develop/pull/9556#discussion_r2289844485
It's the same functionality, minus a otherwise-duplicated empty() check, see ​https://github.com/WordPress/wordpress-develop/blob/6.8.2/src/wp-includes/compat.php#L310-L312

[johnbillion]

PHP also does this internally:

ZEND_HASH_FOREACH_VAL(array, zval *zv) {	RETURN_COPY_DEREF(zv); } ZEND_HASH_FOREACH_END(); 

[desrosj]

These new polyfill functions were detailed in the miscellaneous dev note for developer-focused changed: ​https://make.wordpress.org/core/2025/11/17/miscellaneous-developer-focused-changes-in-6-9/