What does the operator++() do in a linked list iterator?

• A. It moves the iterator to the next node.
• B. It moves the iterator to the previous node.
• C. It inserts a new node after the current one.
• D. It dereferences the data at the current node.

Answer: (A)

Incrementing a linked list iterator moves you forward to the next node, allowing forward traversal through the list. In a singly linked list this is done by following the next pointer from the current node to the next one. It’s a forward step, not an insertion, not a dereference, and not a backward move (that would be a different operator). In many implementations the prefix form returns the updated iterator, while the postfix form returns the old value and then advances.