πŸš€The Event Loop β€” Mastering Async Behavior in JS

🀯 Why JavaScript Feels Asynchronous

JavaScript is single-threaded β€” it runs one task at a time.
But when Hasnide uses things like:

  • setTimeout()

  • fetch()

  • Promises

  • async/await

…it feels asynchronous. That magic is made possible by the event loop.

🧠 Key Components

βœ… 1. Call Stack

  • The main place where JavaScript executes functions.

  • LIFO (Last-In, First-Out) stack.

βœ… 2. Web APIs / Browser APIs

Things like setTimeout, DOM events, fetch() are handled by the browser β€” not the JS engine itself.

βœ… 3. Callback Queue / Task Queue

Once the Web API finishes, the callback is placed into the callback queue.


βœ… 4. The Event Loop

This loop constantly checks:

Is the call stack empty?
If yes β†’ push the next callback from the queue into the stack.

This allows JavaScript to remain non-blocking and responsive.


πŸ”„ Visual Timeline

πŸ§ͺ Code in Action

πŸ” Stack vs Queue vs Microtasks

βœ… Summary

✍️ Written By

πŸ“« chaitanyachopde14@gmail.com


🌟 Inspired By

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Written by

Chaitanya Chopde
Chaitanya Chopde

Hey, I'm Chaitanya Chopde πŸ’» Web Development Learner | Frontend Focused πŸ› οΈ Learning HTML, CSS, JavaScript & Figma ✍️ Writing to share my dev journey, tips & projects 🏷️ #DevsyncLearning | Building one line of code at a time