In a doubly linked list, which pointers are typically stored in each Node?

• A. Only next
• B. Only previous
• C. Both next and previous
• D. Neither

Answer: (C)

In a doubly linked list, each node stores two references: one to the next node and one to the previous node. This bidirectional linkage lets you move forward through the list using the next pointers and move backward using the previous pointers. It also makes inserting or deleting a node in the middle efficient, because you can update the adjacent nodes’ pointers without having to traverse from the head to find a predecessor. At the ends, the first node’s previous reference is null and the last node’s next reference is null, marking the boundaries. If a node had only a next pointer, you’d have a singly linked list; if it had only a previous pointer, forward traversal would be hindered; and if it had neither, there would be no linkage at all.