How to Build an LRU Cache from Scratch in JavaScript

1 · Anton Liberant · March 6, 2026, 3:41 a.m.
Summary
This blog post provides a step-by-step guide to building a Least Recently Used (LRU) cache from scratch in JavaScript. It utilizes a Map and doubly linked list to achieve O(1) operation complexity, along with clear explanations and code examples.