wp-includes/taxonomy.php:3972Gets the subset of $terms that are descendants of $term_id.
$term_idint$termsarray$taxonomystring$ancestorsarrayoptionalarray()array|WP_Errorfunction _get_term_children( $term_id, $terms, $taxonomy, &$ancestors = array() ) { $empty_array = array(); if ( empty( $terms ) ) { return $empty_array; } $term_id = (int) $term_id; $term_list = array(); $has_children = _get_term_hierarchy( $taxonomy ); if ( $term_id && ! isset( $has_children[ $term_id ] ) ) { return $empty_array; } // Include the term itself in the ancestors array, so we can properly detect when a loop has occurred. if ( empty( $ancestors ) ) { $ancestors[ $term_id ] = 1; } foreach ( (array) $terms as $term ) { $use_id = false; if ( ! is_object( $term ) ) { $term = get_term( $term, $taxonomy ); if ( is_wp_error( $term ) ) { return $term; } $use_id = true; } // Don't recurse if we've already identified the term as a child - this indicates a loop. if ( isset( $ancestors[ $term->term_id ] ) ) { continue; } if ( (int) $term->parent === $term_id ) { if ( $use_id ) { $term_list[] = $term->term_id; } else { $term_list[] = $term; } if ( ! isset( $has_children[ $term->term_id ] ) ) { continue; } $ancestors[ $term->term_id ] = 1; $children = _get_term_children( $term->term_id, $terms, $taxonomy, $ancestors ); if ( $children ) { $term_list = array_merge( $term_list, $children ); } } } return $term_list;}Introduced in 2.3.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/taxonomy.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.