get_term_children ( $term_id, $taxonomy )
- (int) $term_id ID of Term to get children.
- (string) $taxonomy Taxonomy Name.
- (array|WP_Error) List of Term IDs. WP_Error returned if `$taxonomy` does not exist.
- Introduced in WordPress: 2.3.0
- Deprecated in WordPress: —
Merge all term children into a single array of their IDs.
This recursive function will merge all of the children of $term into the same
array of term IDs. Only useful for taxonomies which are hierarchical.
Will return an empty array if $term does not exist in $taxonomy.