What are the merits and demerits of array based implementation over linked implementation?

The merits of an array are that it provides the most compact storage mechanism of any data container, and enables constant-time, random access to that data.

The demerits are that insertions and extractions can be costly in terms of performance due to the need to copy/move elements within the array. For large arrays, the cost can become prohibitive. Also, arrays can only be used to store elements of the same type.