Disadvantage of circular linked list over linear linked list

Question

Illustrates the disadvantages of circular linked list over linear linked list?

Answer 1

First, the supposition is that the question is in fact about circular verses linear lists, as against unidirectional verses bidirectional lists.

A linear list is one which holds no valid, but actually a designated invalid value for the reference to the final item's successor, and the initial item's predecessor. The name for that invalid reference value is subject to the implementation language, classically NULL, null or nil.
A circular list only utilizes valid reference values. Forms of rings exist are as: the sentinel ring and the closed ring.

The closed is one which the final item's successor references the initial item, and the initial item's predecessor references the final item.

A feature characteristic of closed rings is which the algorithm cannot usually stop iterating upon an "end reached" criterion. It will be different criteria there, subject to the algorithm. But a closed ring can never be empty; as well this can go within and out of existence.

A sentinel ring is one which consists of one artificial element, the sentinel. Such item functions as the anchor, like the last item's successor, as well as the primary item's predecessor. Sentinel rings consist of a well-defined start and stop (when iteration reaches the sentinel). There the sentinel is an empty ring's single element. The dependable existence of the sentinel rids the ring of any invalid references; a helpful aspect during the design of robust software.