We now check if the book titles are deleted from the first and end of the list which should give us ‘nil’ when and if the list becomes void of contents. list.deleteFirst >> Books: ABDC–Author1 (1) list.deleteFirst >> Books: EFGH–Author2 (2) list.deleteLast >> Books: MNOP–Author1 (1) list.deleteLast >> Books: IJKL–Author3 (3) list.deleteLast >> nil We [...]