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wp_count_terms( array|string $args = array(), array|string $deprecated = '' ): string|WP_Error

Since
2.3.0, 5.6.0
Source
wp-includes/taxonomy.php:1963
Counts how many terms are in taxonomy.

Description

Default $args is 'hide_empty' which can be 'hide_empty=true' or array('hide_empty' => true).

Compatibility

WordPress
since 5.6.0
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

$argsarray|stringoptional
Array or string of arguments. See WP_Term_Query::__construct() for information on accepted arguments. Default empty array.Default: array()
$deprecatedarray|stringoptional
Argument array, when using the legacy function parameter format.
If present, this parameter will be interpreted as $args, and the first function parameter will be parsed as a taxonomy or array of taxonomies.
Default empty.Default: ''

Return value

string|WP_Error
Numeric string containing the number of terms in that taxonomy or WP_Error if the taxonomy does not exist.

Performance profile

How much work a call to wp_count_terms() 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_terms().

Scaling
Constant

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

Instructions
19–39

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 39.

Plugin surface
None

Nothing here hands control to plugin code.

Called by
5

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

What it touches

  • querycontent queryget_terms()called directly
  • hookthird-party callbacksapply_filters()one call below wp_count_terms()

Further down the call graph this can also reach option, cache, serialize 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 · 4 distinct outcomes

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

WhenInstructionsCalls it makes
always19–30wp_parse_args(), get_terms()
is_string($args)26–34taxonomy_exists(), wp_parse_args(), get_terms()
!is_string($args) && is_array($args)27–35wp_is_numeric_array(), wp_parse_args(), get_terms()
is_string($args) && !taxonomy_exists() && is_array($args)31–39taxonomy_exists(), wp_is_numeric_array(), wp_parse_args(), get_terms()

Across PHP versions

Compiles the same on PHP 7.4, 8.1, 8.2, 8.3, 8.4, 8.5 and 8.6-dev: 39 instructions, 19–39 executed per call, 7 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 · 4

Used by · 5

Source code

function wp_count_terms( $args = array(), $deprecated = '' ) {	$use_legacy_args = false; 	// Check whether function is used with legacy signature: `$taxonomy` and `$args`.	if ( $args		&& ( is_string( $args ) && taxonomy_exists( $args )			|| is_array( $args ) && wp_is_numeric_array( $args ) )	) {		$use_legacy_args = true;	} 	$defaults = array( 'hide_empty' => false ); 	if ( $use_legacy_args ) {		$defaults['taxonomy'] = $args;		$args                 = $deprecated;	} 	$args = wp_parse_args( $args, $defaults ); 	// Backward compatibility.	if ( isset( $args['ignore_empty'] ) ) {		$args['hide_empty'] = $args['ignore_empty'];		unset( $args['ignore_empty'] );	} 	$args['fields'] = 'count'; 	return get_terms( $args );}

Changelog

Introduced in 2.3.0. 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.

5.6.0
Changed the function signature so that the $args array can be provided as the first parameter.from the docblock
2.3.0
Introduced.from the docblock

About this page

Parsed data
Generated from the wordpress-develop 7.1.0 tag, from src/wp-includes/taxonomy.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.
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