Source Reference:

• Component: bbPress :: bbp-forum

  File: /bbp-includes/bbp-forum-template.php :: Trac Source Line: 1007

  	 *                                             reply's author id
  	 * @uses bbp_get_reply_author_id() To get the reply's author id
  	 * @uses apply_filters() Calls 'bbp_get_forum_last_reply_author_id' with
  	 *                        the author id and forum id
  	 * @return int Forum's last reply author id
  	 */
  	function bbp_get_forum_last_reply_author_id( $forum_id = 0 ) {
  		$forum_id  = bbp_get_forum_id( $forum_id );
  		$author_id = bbp_get_reply_author_id( bbp_get_forum_last_reply_id( $forum_id ) );
  		return apply_filters( 'bbp_get_forum_last_reply_author_id', $author_id, $forum_id );
  	}
  
  /**
   * Output link to author of last reply of forum
   *
   * @since bbPress (r2625)
   *
   * @param int $forum_id Optional. Forum id
   * @uses bbp_get_forum_last_reply_author_link() To get the forum's last reply's
   *                                               author link