Node Structure

A singly linked list node contains two fields: pseudocode class ListNode: val: integer next: ListNode or null The val field stores the data.

The next field points to the following node, or null if you've reached the last node. To traverse a list, start at the head and follow next pointers until you hit null.

The operation takes $O(n)$ time where $n$ is the list length. Memory layout differs from arrays. Array elements sit in contiguous memory, enabling cache-friendly access.

Linked list nodes scatter across memory, causing more cache misses. That's why arrays are faster for sequential access despite both being $O(n)$. Time: $O(n)$. Space: $O(1)$.