wppaste
WordPress

get_the_post_thumbnail_caption( int|WP_Post|null $post = null ): string

Since
4.6.0
Source
wp-includes/post-thumbnail-template.php:297
Returns the post thumbnail caption.

Compatibility

WordPress
since 4.6.0
PHP
7.4–8.6-dev
  • 6.7.7
  • 6.8.8
  • 6.9.7
  • 7.0.4
  • 7.1.0

Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.

Parameters

$postint|WP_Post|nulloptional
Post ID or WP_Post object. Default is global $post.Default: null

Return value

string
Post thumbnail caption.

Performance profile

How much work a call to get_the_post_thumbnail_caption() 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
Heavy

Reaches the database via get_post().

Scaling
Constant

No loop in the body: the same number of instructions runs whatever you pass in.

Instructions
7–13

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 14.

Plugin surface
None

Nothing here hands control to plugin code.

Called by
1

1 place in core call this, so the cost is paid more often than your own code shows.

What it touches

  • querycontent queryget_post()one call below get_the_post_thumbnail_caption()
  • hookthird-party callbacksapply_filters()one call below get_the_post_thumbnail_caption()

Further down the call graph this can also reach cache, serialize, option and transient. Those are the worst case, several calls deep and usually down an error path, not what a normal call pays.

What one call costs · 2 distinct outcomes

One number would be a lie: the work depends on which branch runs. These are every distinct cost get_the_post_thumbnail_caption() can have, taken from its control-flow graph on PHP 8.5.

WhenInstructionsCalls it makes
always7get_post_thumbnail_id()
always12–13get_post_thumbnail_id(), wp_get_attachment_caption()

Across PHP versions

Compiles the same on PHP 7.4, 8.1, 8.2, 8.3, 8.4, 8.5 and 8.6-dev: 14 instructions, 7–13 executed per call, 2 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.

Uses · 2

Used by · 1

Source code

View on Trac View on GitHub 

function get_the_post_thumbnail_caption( $post = null ) {	$post_thumbnail_id = get_post_thumbnail_id( $post ); 	if ( ! $post_thumbnail_id ) {		return '';	} 	$caption = wp_get_attachment_caption( $post_thumbnail_id ); 	if ( ! $caption ) {		$caption = '';	} 	return $caption;}

Changelog

Introduced in 4.6.0. One change between 6.7.7 and 7.1.0.

  1. 6.7.7
  2. 6.8.8
  3. 6.9.7
  4. 7.0.4
  5. 7.1.0

Signature, return type and hooks compared across 5 parsed releases.

6.8.8
Parameter $post retyped from int|WP_Post to int|WP_Post|null.verified against source
4.6.0
Introduced.from the docblock

About this page

Parsed data
Generated from the wordpress-develop 6.8.8 tag, from src/wp-includes/post-thumbnail-template.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.
Corrections
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