JavaScript Non-Blocking Execution

🧠 Day 3 of 21 days challenge JavaScript Event Loop 🤯 Event Loop is a mechanism in JavaScript that handles execution of asynchronous code. It continuously checks the call stack and callback queue. If the stack is empty, it moves tasks from the queue to the stack for execution. For example :- console.log("Start"); console.log("End"); console.log("Timeout"); Wait… why this order? Because JavaScript doesn’t run everything instantly. It uses: • Call Stack • Web APIs • Callback Queue Event Loop decides what runs next. 💤For easy understanding :- Event Loop = decides execution order Sync code runs first Async code waits in queue Then runs after the stack is empty 👉 That’s why “Timeout” runs last This changed how I understand async code 🚀 #JavaScript #EventLoop #Async

I just published my first video on BitGuru. It explains JavaScript closures — visually, in under 3 minutes. No jargon walls. No "let me read the MDN definition." Just a puzzle that breaks your expectations, and a mental model that makes closures obvious. If you write JavaScript, closures aren't optional. This video makes them intuitive. https://lnkd.in/gpVMQE52

Async JavaScript finally made sense… At first, it felt messy and confusing Now? It’s one of the most powerful things in JavaScript. 💡 Quick breakdown: Callbacks → simple but messy (callback hell) 🔹 Promises → cleaner async handling 🔹 Async/Await → readable, simple, powerful ⚙️ Used everywhere: API calls (Fetch/Axios), timers, user events 📌 I struggled most with callbacks — but async/await changed everything.

JavaScript Concept: What is Tree Shaking? Answer: Tree Shaking removes unused code from your bundle. Example: import { add } from "./utils" If other functions are unused, they won’t be included. Explanation: Bundlers like: • Webpack • Vite • Rollup analyze imports and remove dead code. Benefits: 1. smaller bundle size 2. faster load time 3. better performance Important: Tree shaking works best with ES modules (import/export). Follow-up: Have you checked your bundle size recently? #javascript #WebPerformance #FrontendOptimization

Can you explain the JavaScript event loop? Not because the concept is hard, but because explaining it clearly is what actually matters. Here’s the simplest way to break it down: JavaScript runs in a single thread, using a call stack to execute code. 1. Synchronous code runs first → Functions are pushed to the call stack and executed immediately 2. Async tasks are handled by the browser/environment → e.g. setTimeout, fetch, DOM events 3. Once the call stack is empty → the event loop starts working It processes queues in this order: 👉 Microtasks first (Promises, queueMicrotask) 👉 Then macrotasks (setTimeout, setInterval, I/O) Why? - A and D are synchronous → executed first - Promise (C) → microtask queue → runs next - setTimeout (B) → macrotask → runs last Explaining it step by step is simple — but doing it clearly makes all the difference. #Frontend #JavaScript #WebDevelopment #TechInterviews #SoftwareEngineering

A small but important JavaScript concept I learned. Comparing objects can be tricky: {} === {} // false Even though both objects look identical, the result is false. Why? Because JavaScript compares objects by reference, not by value. Each {} creates a new object in memory, so they are different references. This is important when working with validations and comparisons in backend logic. Understanding these small details helps avoid subtle bugs.

🚀 Understanding Async JavaScript: async/await vs .then() Today I practiced handling asynchronous operations in JavaScript using both Promises and async/await 🔥 📌 What I explored: 💡 Key Insight:While .then() works perfectly, async/await makes asynchronous code look synchronous — improving readability and maintainability. 🧠 Example takeaway: Both approaches are powerful — choosing the right one depends on the use case! 🌐 API used: JSONPlaceholder for dummy data testing 📈 Small steps every day towards mastering JavaScript! #JavaScript #AsyncAwait #WebDevelopment #FrontendDeveloper #CodingJourney #LearnInPublic #100DaysOfCode

If you choose a JavaScript framework that can't produce accessible code, there isn't much chance you'll be able to change it at a later date for example. Even the things that can be changed come at a cost. Léonie Watson

⚡ JavaScript Concept: Promises vs. Async/Await Stop the callback confusion! Choose the right tool for your async code. 🚀 🟢 Promises → The Foundation Action: Handles async operations via .then() and .catch(). Best for: Simple API fetches and parallel tasks. 🔴 Async/Await → The Standard Action: Cleaner syntax that reads like synchronous code. Best for: Complex logic and sequential API calls. #javascript #frontenddevelopment #reactjs #webperformance #webdevelopment

JavaScript Event Loop — simplified 👇 Understanding this changed how I debug async code. ▪️ Call Stack handles execution ▪️ Web APIs handle async tasks ▪️ Event Loop manages flow ▪️ Microtasks (Promises) run before callbacks ⚡ Once this clicks, JavaScript becomes much easier. What’s the most confusing part of JS for you? #JavaScript #FrontendDevelopment #WebDevelopment