get_ancestors( int $object_id, string $object_type = ”, string $resource_type = ” )

获取给定对象的祖先ID数组。
Get an array of ancestor IDs for a given object.

目录锚点：#参数#返回#源码#笔记

参数（Parameters）

返回（Return）

（int[]）层次结构中从低到高的祖先id数组。

源码（Source）

/**
 * Get an array of ancestor IDs for a given object.
 *
 * @since 3.1.0
 * @since 4.1.0 Introduced the `$resource_type` argument.
 *
 * @param int    $object_id     Optional. The ID of the object. Default 0.
 * @param string $object_type   Optional. The type of object for which we'll be retrieving
 *                              ancestors. Accepts a post type or a taxonomy name. Default empty.
 * @param string $resource_type Optional. Type of resource $object_type is. Accepts 'post_type'
 *                              or 'taxonomy'. Default empty.
 * @return array An array of ancestors from lowest to highest in the hierarchy.
 */
function get_ancestors( $object_id = 0, $object_type = '', $resource_type = '' ) {
	$object_id = (int) $object_id;

	$ancestors = array();

	if ( empty( $object_id ) ) {

		/** This filter is documented in wp-includes/taxonomy.php */
		return apply_filters( 'get_ancestors', $ancestors, $object_id, $object_type, $resource_type );
	}

	if ( ! $resource_type ) {
		if ( is_taxonomy_hierarchical( $object_type ) ) {
			$resource_type = 'taxonomy';
		} elseif ( post_type_exists( $object_type ) ) {
			$resource_type = 'post_type';
		}
	}

	if ( 'taxonomy' === $resource_type ) {
		$term = get_term($object_id, $object_type);
		while ( ! is_wp_error($term) && ! empty( $term->parent ) && ! in_array( $term->parent, $ancestors ) ) {
			$ancestors[] = (int) $term->parent;
			$term = get_term($term->parent, $object_type);
		}
	} elseif ( 'post_type' === $resource_type ) {
		$ancestors = get_post_ancestors($object_id);
	}

	/**
	 * Filter a given object's ancestors.
	 *
	 * @since 3.1.0
	 * @since 4.1.1 Introduced the `$resource_type` parameter.
	 *
	 * @param array  $ancestors     An array of object ancestors.
	 * @param int    $object_id     Object ID.
	 * @param string $object_type   Type of object.
	 * @param string $resource_type Type of resource $object_type is.
	 */
	return apply_filters( 'get_ancestors', $ancestors, $object_id, $object_type, $resource_type );
}

笔记（Notes）

给定以下类别层次结构（带ID）：
给定a页层次结构（带ID）：