Which operation would you use to determine if a particular value exists in a linked list?

• A. Search
• B. Insert
• C. Delete
• D. Copy

Answer: (A)

To check whether a specific value exists in a linked list, you perform a search. A linked list doesn’t support direct access to arbitrary positions, so you start at the head and walk node by node, comparing each node’s value with the target. If a match is found, you can stop and confirm the value is present; if you reach the end of the list without finding it, the value isn’t in the list. This is typically O(n) in the worst case because you may need to inspect every node. In contrast, inserting adds a new node, deleting removes a node, and copying creates duplicates; these operations don’t by themselves determine whether a value is already present.