get_objects_in_term()

get_objects_in_term() — Retrieves object IDs of valid taxonomy and term. The strings of $taxonomies must exist before this function will continue. On failure of finding a valid taxonomy, it will return a WP_Error. The $terms aren’t checked the same as $taxonomies, but still need to exist for object IDs to be returned. It is possible to change the order that object IDs are returned by using $args with either ASC or DESC array. The value should be in the key named ‘order’.

Inputs: $term_ids (int|int[]): Term ID or array of term IDs of terms that will be used. $taxonomies (string|string[]): String of taxonomy name or Array of string values of taxonomy names. $args (array|string): Change the order of the object IDs. Field $order (string): Order to retrieve terms. Accepts ‘ASC’ or ‘DESC’. Default ‘ASC’.

Returns string[]|WP_Error: An array of object IDs as numeric strings on success, WP_Error if the taxonomy does not exist.