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Hand-written tutorials, ordered as a recommended learning path.

1. 41 Temporal API Guide Explore the Temporal API for JavaScript -- a modern, immutable, and time-zone-aware replacement for the legacy Date object. 6 min read →
2. 42 WeakMap & WeakSet Understand JavaScript WeakMap and WeakSet, their garbage collection behavior, and practical use cases like caching, private data, and DOM metadata. 6 min read →
3. 43 Iterators & Generators A deep dive into JavaScript iterators and generators: the iterator protocol, Symbol.iterator, generator functions, yield, async generators, and practical patterns for lazy evaluation and data pipelines. 11 min read →
4. 44 Web Workers Run JavaScript in background threads with Web Workers — dedicated workers, shared workers, message passing, and offloading heavy computation. 3 min read →
5. 45 ESM vs CJS A practical comparison of ES Modules and CommonJS: how they load, how they differ, interop strategies, and how to choose for a new project. 5 min read →
6. 46 map, filter, reduce Master the three most powerful array methods in JavaScript — map, filter, and reduce — with practical examples, chaining patterns, and performance tips. 4 min read →
7. 47 Async/Await Tutorial Master async and await in JavaScript — write asynchronous code that reads like synchronous code, handle errors with try/catch, and parallelize work with Promise.all. 4 min read →
8. 48 Closures & Scope Understand JavaScript closures and lexical scope — see how inner functions remember outer variables, and learn the patterns that closures enable. 4 min read →
9. 49 Promises Deep Dive Go beyond the basics of JavaScript promises — explore the microtask queue, error propagation, cancellation patterns, and advanced combinators like any and allSettled. 4 min read →
10. 50 The this Keyword Demystify the JavaScript this keyword — understand how it changes by call site, why arrow functions differ, and how to bind context without surprises. 4 min read →
11. 51 React Context Guide Learn how to use React's Context API to share state across your component tree without prop drilling — with patterns, performance tips, and common mistakes to avoid. 4 min read →
12. 52 Custom Hooks Patterns Learn powerful patterns for building React custom hooks — extracting logic, composing hooks, handling cleanup, and designing clean APIs your team will love. 5 min read →
13. 53 React Hooks A practical deep dive into useState, useEffect, useMemo, useCallback, and useRef. Learn when to reach for each hook and the traps that ruin React code. 6 min read →
14. 54 useEffect Mistakes Avoid the most common useEffect mistakes — missing dependencies, infinite loops, stale closures, and effects that should not be effects in the first place. 4 min read →
15. 55 Generics Intro An approachable introduction to TypeScript generics — learn type parameters, constraints, defaults, and how to build reusable type-safe functions and components. 4 min read →
16. 56 Closures A practical guide to JavaScript closures, lexical scope, the classic loop bug, and the patterns that make closures genuinely useful in production code. 7 min read →
17. 57 DOM A modern guide to vanilla DOM manipulation: query selectors, creating and inserting nodes, event handling, delegation, and when a framework is actually worth it. 7 min read →
18. 58 Event loop Build an accurate mental model of the JavaScript event loop, the call stack, web APIs, the task and microtask queues, and why setTimeout zero is not really zero. 7 min read →
19. 59 Fetch API A practical guide to the Fetch API: GET and POST requests, JSON, headers, error handling, AbortController, and the 4xx/5xx rejection gotcha that bites everyone. 7 min read →
20. 60 Prototypes Understand the JavaScript prototype chain, how Object.create works, what class syntax desugars to, and why this still matters in modern code. 7 min read →