wppaste
WordPress

wp_attachment_is_image( int|WP_Post $post = null ): bool

Since
2.1.0, 4.2.0
Source
wp-includes/post.php:7169
Determines whether an attachment is an image.

Description

For more information on this and similar theme functions, check out the https://developer.wordpress.org/themes/basics/conditional-tags/ Conditional Tags article in the Theme Developer Handbook.

Compatibility

WordPress
since 4.2.0
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_Postoptional
Attachment ID or object. Default is global $post.Default: null

Return value

bool
Whether the attachment is an image.

Performance profile

How much work a call to wp_attachment_is_image() 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
6

Executed per call on PHP 8.5. The body compiles to 6.

Plugin surface
None

Nothing here hands control to plugin code.

Called by
16

16 places 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 wp_attachment_is_image()

Further down the call graph this can also reach hook, 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 · 1 distinct outcome

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

WhenInstructionsCalls it makes
always6wp_attachment_is()

Across PHP versions

Compiles the same on PHP 7.4, 8.1, 8.2, 8.3, 8.4, 8.5 and 8.6-dev: 6 instructions, 6 executed per call, 0 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 · 1

Used by · 16

Show all 16

Source code

function wp_attachment_is_image( $post = null ) {	return wp_attachment_is( 'image', $post );}

Changelog

Introduced in 2.1.0. Unchanged from 6.7.7 through 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.

4.2.0
Modified into wrapper for wp_attachment_is() and allowed WP_Post object to be passed.from the docblock
2.1.0
Introduced.from the docblock

About this page

Parsed data
Generated from the wordpress-develop 7.0.4 tag, from src/wp-includes/post.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.
Corrections
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