wppaste
WordPress

get_category_children( int $id, string $before = '/', string $after = '', array $visited = array() ): string

Since
1.2.0
Source
wp-includes/deprecated.php:1275
Retrieve category children list separated before and after the term IDs.

Compatibility

Deprecated in WordPress 2.8.0. Use get_term_children()

WordPress
since 1.2.0
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

$idint
Category ID to retrieve children.
$beforestringoptional
Prepend before category term ID. Default '/'.Default: '/'
$afterstringoptional
Append after category term ID. Default empty string.Default: ''
$visitedarrayoptional
Category Term IDs that have already been added.
Default empty array.Default: array()

Return value

string

Performance profile

How much work a call to get_category_children() 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
Scales with input

The body loops, so the work grows with what you pass in.

Instructions
12–30

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 55.

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

  • hookthird-party callbacksdo_action()one call below get_category_children()
  • querycontent queryget_terms()one call below get_category_children()

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 · 3 distinct outcomes

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

WhenInstructionsCalls it makes
$id == 012_deprecated_function()
$id != 019–20_deprecated_function(), get_all_category_ids()
$id != 0 && !$cat_ids && $cat_id != false && is_wp_error()30_deprecated_function(), get_all_category_ids(), get_category(), is_wp_error()

Across PHP versions

PHPCompiledExecutedBranchesNotes
8.6-dev5512–307
8.55512–307
8.45512–3073 fewer instructions than PHP 8.3
8.35812–307
8.25812–307
8.15812–307
7.45812–307

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 · 5

Used by · 1

Source code

function get_category_children( $id, $before = '/', $after = '', $visited = array() ) {	_deprecated_function( __FUNCTION__, '2.8.0', 'get_term_children()' );	if ( 0 == $id )		return ''; 	$chain = '';	/** TODO: Consult hierarchy */	$cat_ids = get_all_category_ids();	foreach ( (array) $cat_ids as $cat_id ) {		if ( $cat_id == $id )			continue; 		$category = get_category( $cat_id );		if ( is_wp_error( $category ) )			return $category;		if ( $category->parent == $id && !in_array( $category->term_id, $visited ) ) {			$visited[] = $category->term_id;			$chain .= $before.$category->term_id.$after;			$chain .= get_category_children( $category->term_id, $before, $after );		}	}	return $chain;}

Changelog

Introduced in 1.2.0. 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.

2.8.0
Deprecated. Use get_term_children()from the docblock
1.2.0
Introduced.from the docblock

About this page

Parsed data
Generated from the wordpress-develop 6.7.7 tag, from src/wp-includes/deprecated.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.
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