Master JavaScript from basics to advanced
Understand the difference between JavaScript microtasks and macrotasks. Learn the exact execution order, which APIs use each queue, starvation risks, and how to use queueMicrotask correctly.
Compare JavaScript callbacks and Promises side by side. Learn how they handle async operations differently, the problems callbacks have, how Promises solve them, and when to use each pattern.
Learn what callback hell is, why it happens, and five concrete techniques to eliminate it from your JavaScript code including named functions, Promises, and async/await.
Master JavaScript Promise chaining with .then(), .catch(), and .finally(). Learn how values flow through chains, common mistakes to avoid, and patterns for sequential and parallel async operations.
Learn every technique for handling Promise rejections in JavaScript: .catch(), try/catch with async/await, the unhandledrejection event, rejection chaining, and best practices to prevent silent failures.
Master Promise.all, Promise.allSettled, Promise.race, and Promise.any in JavaScript. Learn parallel vs sequential execution, error handling strategies, and practical patterns for concurrent async operations.
Learn how Promise.allSettled enables partial-success patterns in JavaScript. Understand how it differs from Promise.all, handle mixed outcomes gracefully, and build resilient API calls that never fail silently.
Master Promise.race in JavaScript. Learn how it works, when to use it, how to build robust timeout wrappers, cancel slow requests with AbortController, and understand the difference from Promise.any.
Master async/await in JavaScript from the ground up. Learn how async functions return Promises, how await suspends execution, error handling with try/catch, parallel patterns, and common pitfalls to avoid.
Learn step-by-step how to convert JavaScript Promise chains to async/await syntax. See before/after refactoring examples, handling .catch() recovery, parallel operations, and wrapping legacy callback APIs.
Go beyond basic try/catch in JavaScript. Learn advanced error handling patterns including typed error checking, rethrowing, finally semantics, error boundaries, global handlers, and building a robust error handling strategy.
Master async error handling in JavaScript with try/catch and async/await. Learn how await transforms rejections into throws, handle errors in parallel operations, build reliable async error boundaries, and avoid common pitfalls.