array_first( array $array ): mixed|null
- Since
- 6.9.0
- Source
wp-includes/compat.php:657
array_first() function added in PHP 8.5.Description
Returns the first element of an array.
Compatibility
- WordPress
- since 6.9.0
- PHP
- 7.4–8.6-dev
- 6.7.7
- 6.8.8
- 6.9.7
- 7.0.4
- 7.1.0
Present in 3 of the 5 tracked releases, added in 6.9.0, and compiles on PHP 7.4 through 8.6-dev.
Parameters
$arrayarray- The array to get the first element from.
Return value
mixed|null- The first element of the array, or null if the array is empty.
Performance profile
How much work a call to array_first() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.
- Cost class
- Trivial
- Scaling
- Constant
- Instructions
- 4–7
- Plugin surface
- None
- Called by
- 3
Touches nothing outside its own arguments.
No loop in the body: the same number of instructions runs whatever you pass in.
Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 10.
Nothing here hands control to plugin code.
3 places in core call this, so the cost is paid more often than your own code shows.
What one call costs · 1 distinct outcome
One number would be a lie: the work depends on which branch runs. These are every distinct cost array_first() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
| always | 4–7 | none |
Across PHP versions
Compiles the same on PHP 7.4, 8.1, 8.2, 8.3, 8.4, 8.5 and 8.6-dev: 10 instructions, 4–7 executed per call, 3 branches. The work does not change between versions.
An instruction is not a fixed amount of time, so a matching count is not necessarily the same speed; what it rules out is a difference in the work itself.
Used by · 3
- WP_REST_Widget_Types_Controller::encode_form_data()An RPC-style endpoint which can be used by clients to turn user input in a widget admin form into an encoded instance object.
- Walker::walk()Displays array of elements hierarchically.
- esc_url()Checks and cleans a URL.
Source code
function array_first( array $array ) { // phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.arrayFound if ( empty( $array ) ) { return null; } foreach ( $array as $value ) { return $value; } }Changelog
Introduced in 6.9.0. Unchanged from 6.9.7 through 7.1.0.
Signature, return type and hooks compared across 3 parsed releases.
About this page
- Parsed data
- Generated from the wordpress-develop 7.1.0 tag, from
src/wp-includes/compat.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it. - Corrections
- Something wrong on this page? Report it and it gets fixed in the next regeneration.