wp_update_comment_count()

wp_update_comment_count() — Updates the comment count for post(s). When $do_deferred is false (is by default) and the comments have been set to be deferred, the post_id will be added to a queue, which will be updated at a later date and only updated once per post ID. If the comments have not be set up to be deferred, then the post will be updated. When $do_deferred is set to true, then all previous deferred post IDs will be updated along with the current $post_id.

Inputs: $post_id (int|null): Post ID. $do_deferred (bool): Optional. Whether to process previously deferred post comment counts. Default false.

Returns bool|null: True on success, false on failure or if post with ID does not exist.