term_is_ancestor_of( int|object $term1, int|object $term2, string $taxonomy ): bool
- Since
- 3.4.0
- Source
wp-includes/taxonomy.php:1685
Description
You can use either an ID or the term object for both parameters.
Compatibility
- WordPress
- since 3.4.0
- 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
$term1int|object- ID or object to check if this is the parent term.
$term2int|object- The child term.
$taxonomystring- Taxonomy name that $term1 and
$term2belong to.
Return value
bool- Whether
$term2is a child of$term1.
Performance profile
How much work a call to term_is_ancestor_of() 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
- Scaling
- Constant
- Instructions
- 10–37
- Plugin surface
- None
- Called by
- 3
Reaches the database via get_term().
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 39.
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 it touches
- querycontent query
get_term()called directly - hookthird-party callbacks
apply_filters()one call below term_is_ancestor_of()
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 · 6 distinct outcomes
One number would be a lie: the work depends on which branch runs. These are every distinct cost term_is_ancestor_of() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
isset($term1) && isset($term2) | 10–16 | none |
| always | 15–21 | get_term() |
!isset($term1) && !isset($term2) | 20–26 | get_term(), get_term() |
isset($term1) && isset($term2) && !empty($term1) && !empty($term2) | 27 | get_term(), term_is_ancestor_of() |
!empty($term1) && !empty($term2) | 32 | get_term(), get_term(), term_is_ancestor_of() |
!isset($term1) && !isset($term2) && !empty($term1) && !empty($term2) | 37 | get_term(), get_term(), get_term(), term_is_ancestor_of() |
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, 10–37 executed per call, 5 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
- get_term()Gets all term data from database by term ID.
- term_is_ancestor_of()Checks if a term is an ancestor of another term.
Used by · 3
- cat_is_ancestor_of()Checks if a category is an ancestor of another category.
- term_is_ancestor_of()Checks if a term is an ancestor of another term.
- wp_insert_category()Updates an existing Category or creates a new Category.
Source code
function term_is_ancestor_of( $term1, $term2, $taxonomy ) { if ( ! isset( $term1->term_id ) ) { $term1 = get_term( $term1, $taxonomy ); } if ( ! isset( $term2->parent ) ) { $term2 = get_term( $term2, $taxonomy ); } if ( empty( $term1->term_id ) || empty( $term2->parent ) ) { return false; } if ( $term2->parent === $term1->term_id ) { return true; } return term_is_ancestor_of( $term1, get_term( $term2->parent, $taxonomy ), $taxonomy );}Changelog
Introduced in 3.4.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
About this page
- Parsed data
- Generated from the wordpress-develop 6.9.7 tag, from
src/wp-includes/taxonomy.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.