JavaScript

Stop reinventing loops — master these core functions to write cleaner, more expressive code. Introduction: Why This Matters Every JavaScript developer has been guilty of writing a messy for loop that tries to do too much. I’ve been there: nested loops, counters, conditionals — all in one block of code. It works, but it’s ugly, error-prone, and not something you…

A practical, senior-dev guide to merging arrays without surprises — covering performance, edge cases, TypeScript tips, and real-world recipes. Introduction If you write JavaScript daily, you combine arrays all the time — merging props in React, stitching paginated results, building search indexes, or flattening data from APIs. And every few lines, you face a tiny fork in the road:…

A practical guide to writing correct, fast, and readable sorts in JavaScript — with copy-paste utilities you’ll reuse forever. Introduction Sorting is one of those “it should be simple” tasks that quietly spawns bugs: This guide shows how to sort without surprises. We’ll cover the rules the engine follows, safe comparator patterns, immutability, locale-aware string sorts, multi-key sorts,…

Two common patterns in JavaScript to deduplicate arrays — and when to use each. Introduction Every developer eventually faces this: const arr = [1, 2, 2, 3, 4, 4, 5]; 👉 How do you get: [1, 2, 3, 4, 5] There are dozens of tricks floating around — Set, filter, reduce, Lodash’s uniq. But the two most common in vanilla…

From simple recursion to powerful ES2025 tricks Introduction You’ve probably run into this before: const nested = [1, [2, [3, [4, 5]]]]; Now you want: [1, 2, 3, 4, 5] Flattening arrays sounds trivial… until you see the many ways to do it in JavaScript. Should you use recursion? reduce? A built-in method like .flat()? Or go…