What is the purpose of the copy constructor in a linked list?

• A. To perform a shallow copy
• B. To create a new list by deep-copying another list
• C. To delete all nodes in the original
• D. To reserve memory for future nodes

Answer: (B)

The copy constructor for a linked list is used to produce an entirely new list that is an independent duplicate of an existing one. It does a deep copy by allocating new nodes and copying each node’s data, then linking those new nodes in the same order as the source. This yields two separate lists: changes to one won’t affect the other, and destroying one won’t invalidate the other. If the source is empty, the new list is empty; otherwise, you clone every node as you traverse.

A shallow copy would only copy pointers to the existing nodes, causing both lists to share the same nodes and leading to problems when either list is modified or destroyed. Deleting all nodes in the original is a cleanup task, not part of copying, and reserving memory for future nodes isn’t the responsibility of the copy constructor.