java.util · java.base · since Java 1.2

LinkedList

declaration

public class LinkedList<E> extends AbstractSequentialList<E>
        implements List<E>, Deque<E>, Cloneable, Serializable

Doubly-linked list implementing both List and Deque. Almost always slower than ArrayList/ArrayDeque in practice — node allocations and pointer chasing dominate.

get(i) walks the chain — O(n); iteration takes a cache miss per node
Legitimate niche: cursor-based editing via ListIterator

Key methods

`void addFirst(E) / addLast(E)`	O(1) insertion at either end — the actual niche.
`E peekFirst() / E peekLast()`	O(1) inspection without removal; null if empty.
`E pollFirst() / E pollLast()`	O(1) null-returning removal from either end.
`void push(E) / E pop()`	Stack aliases for addFirst()/removeFirst().
`ListIterator<E> listIterator(int index)`	Cursor with O(1) insert/remove at the cursor position — the one real edge over ArrayList.