What is a LinkedList?

LinkedList is one of the implementations of the List interface in Java. It represents a doubly linked list, where each element (node) contains a reference to the previous and next nodes, as well as the stored value.

Main characteristics:

• Dynamic size: Can grow or shrink as elements are added or removed.
• Unindexed access: Access to elements is performed by sequential traversal, not directly by index (as in ArrayList).
• Efficient insertion/removal operations: Inserting or removing elements at the beginning or end of the list, as well as inside it, is usually very fast (O(1) or O(n), depending on the position and the need for searching).
• Inefficient index access: Accessing an element by its index requires traversing the list from the beginning or end, making this operation slow (O(n)).
• Implements interfaces List, Deque, Cloneable, Serializable: This allows it to be used as a list, queue, or stack.

It is used when insert and delete operations are frequent, especially at the beginning or end of the list, and when frequent random access to elements by index is not required. Otherwise, it is preferable to use ArrayList.