Prateek Sachdeva’s Post

Coming from a C++ background, I was used to working with a true multithreaded language, whre multiple functions could wrestle for CPU time. Then I hit JavaScript… and realized it’s single-threaded. Only one function can actually run at a time. which changed how i approach problems. I was working on a small project — basically just making a div move randomly across the screen. Sounds simple, right? But when you give it independent X and Y targets, things get chaotic fast. The movement looks alive, unpredictable, like it’s thinking. That’s when I learned about requestAnimationFrame(). At first, I thought it just “runs things continuously.” Nope. It schedules them — about 60 times a second. You’re not looping; you’re politely asking the browser to let your code run again at the next frame and if you don’t structure it right, like putting requestAnimationFrame() inside your function but not calling it again outside, your function just fires once and quits. Feels small, but understanding this changed how I think about JavaScript, not as a slower , but as a completely different beast that plays by its own rules. #javascript #frontend

💻 JavaScript Code Challenges: Level Up Your Skills 💻 Want to truly master JavaScript? Stop memorizing and start practicing with real engine-level challenges: 1️⃣ Scope & Lexical Environment let a = 10; function test() { let a = 20; console.log(a); } test(); // ? console.log(a); // ? 2️⃣ Closures function counter() { let count = 0; return function() { count++; return count; } } const inc = counter(); console.log(inc()); // ? console.log(inc()); // ? 3️⃣ Hoisting & TDZ console.log(x); // ? let x = 5; console.log(y); // ? var y = 10; ✅ Challenge yourself: Predict the output before running the code. Understand why it behaves that way. That’s how you think like the JS engine! #JavaScript #CodingChallenge #Closures #Scope #Hoisting #LexicalScoping #TDZ #DevCommunity #WebDevelopment #ProgrammingTips #CleanCode

👀 JS Macro vs Micro tasks: A very important concept of JS, often ignored, but can put you in hours long debugging sessions 😂 🧩 Basically, JS doesn’t just have one queue — it has two (if categorized majorly on priority basis): Macrotasks: timers, I/O, setTimeout, etc. Microtasks: promises, queueMicrotask, process.nextTick etc. Microtasks run right after the current stack — before the next macrotask. So even a setTimeout(..., 0) gets delayed behind promises. That’s why code like attached image prints in this order: ``` promise timeout ``` You can read more about this in the article below: https://lnkd.in/gEjWn3_S #JavaScript #NodeJS #EventLoop #AsyncProgramming #WebDevelopment #SoftwareEngineering #LearnInPublic

💡 The Curious Case of NaN in JavaScript Ever tried this in JavaScript? 👇 console.log(typeof NaN); // 🤔 Surprise! The output is "number" 😄 That’s right — NaN (Not-a-Number) is ironically of type number! It represents an invalid numeric operation — like dividing 0 / 0 or parsing Number("abc"). Think of it like this: “NaN is JavaScript’s polite way of saying — I tried to do the math, but it doesn’t make sense!” 😅 #JavaScript #CodingTips #WebDevelopment #FrontEnd #LearnJavaScript #CodeNewbie #TechCommunity #DeveloperLife #ProgrammingHumor

Ever felt lost in the complexities of the Node.js EVENT LOOP? 🤔 Let's demystify this core concept for better JavaScript performance! The Node.js Event Loop (powered by V8 and libUV) is the HEARTBEAT ❤️ of asynchronous JavaScript. Understanding it is CRUCIAL for writing efficient Node.js applications. Here are three key takeaways: 💡 Grasp the difference between BLOCKING and NON-BLOCKING I/O. Blocking I/O halts the entire process, non-blocking doesn't. ⏱️ Understand the nuances of `setImmediate` vs. `setTimeout(0)`. While seemingly similar, they behave differently in the event loop's execution order. `setImmediate` prioritizes I/O cycle, while `setTimeout(0)` goes to the timer queue. 🧵 Optimize your UV_THREADPOOL_SIZE. This determines the number of threads available for asynchronous operations. Increasing it can boost performance for CPU-intensive tasks. What's YOUR favorite Node.js performance tip? Share in the comments! 👇 #Nodejs #JavaScript #EventLoop #Asynchronous #Programming #Backend #Performance

➕ "10" + 10 = "1010" 🤔 but "10" - 10 = 0 ❓ Thinking JavaScript is weak at Math? 🤨 Nah, it just has other intentions with the same operators! 😉 👉 When the + operator comes into play, if any operand is a string, JS thinks — “Alright, let’s join them!” 🔗 👉 So "10" + 10 becomes "1010" — simple concatenation magic ✨ But when it’s the - operator’s turn, it’s all business 🧮 👉 JS tries to convert both sides to numbers → "10" - 10 gives 0 And if the string isn’t numeric, you’ll meet NaN 😅 👉 JS isn’t confused — it’s just context-aware. Smart, right? 💡 #JavaScript #WebDevelopment #CodingTips #JSFacts #Frontend #LearnJS #TypeCoercion #Developers #ProgrammingHumor

In recent years many front-end devs have focused on frameworks like Angular, React (and yes, I know that it is library 😅) and Vue.js — yet surprisingly few keep pace with modern JavaScript (ES6+). ECMAScript 2025 (ES2025) was officially approved in June 2025. What’s new (and worth using now): - Native JSON modules & import attributes: e.g. import config from './config.json' with { type: 'json' }; - Iterator helper methods: now iterables can do .filter(), .map(), .take(), .toArray() etc — not just arrays. - Powerful new Set methods: intersection, union, difference, isSubsetOf, etc — making set operations clean. - RegExp.escape() method + regex pattern modifiers (e.g., duplicate named capture groups) — better regex support. - Support for 16-bit float typed arrays (Float16Array) and numeric operations — good for perf/specialised code. #ES6 #angular #react #vue #frontend

💡 Understanding How JavaScript Really Works Ever wondered what actually happens when you run JavaScript? 🤔 Here’s a simple breakdown 👇 🔹 1. You write code let name = "JavaScript"; console.log(name); 🔹 2. The V8 Engine (in Chrome or Node.js) takes over It reads your code, turns it into machine code, and runs it — super fast ⚡ 🔹 3. Just-in-Time Compilation (JIT) V8 doesn’t just interpret code — it compiles and optimizes it while running. That’s how JS became one of the fastest languages on the web. 🔹 4. Memory & Garbage Collection V8 automatically cleans up unused memory so your app keeps running smoothly 🧹 🔹 5. Hidden Optimizations It uses smart tricks like hidden classes and inline caching to speed up repeated code. ✨ Why this matters: When you know how JavaScript actually runs, you can write cleaner, faster, and more efficient code. Think less “just code” — more “understand the engine.” 🧠 #JavaScript #V8 #WebDevelopment #Coding #Learning #NodeJS #Frontend

Ever seen a variable live even after its function dies? That’s Closure — the memory ninja of JavaScript 🧠 One of JavaScript’s most powerful (and tricky) features 💡 Let’s look at a simple example 👇 function counter() { let count = 0; return function () { count++; console.log(count); }; } const increment = counter(); increment(); // 1 increment(); // 2 increment(); // 3 Wait… how does count still remember its value? Didn’t the counter() function finish already? 😅 Here’s the magic 🪄 > A closure allows a function to “remember” the variables from the scope in which it was created — even after that scope is gone. In this example, The inner function still has access to count, Because it closes over the variables from its outer function. That’s why we call it a Closure 🔁 Closures are the reason we can create: ✅ Private variables ✅ Function factories ✅ Modular, memory-efficient code In short — > A closure is how JavaScript gives functions memory 🧠 #JavaScript #Closures #WebDevelopment #Frontend #MERNStack #NodeJS #ReactJS #Coding #SoftwareEngineering #Developers #JSFundamentals

Top 10 JavaScript Libraries to Learn in 2025 The JavaScript ecosystem never slows down — new frameworks rise, and existing ones evolve. So, which libraries are worth your time in 2025? In this detailed guide, we explore the top 10 JavaScript libraries every developer should learn this year — from React, Vue 3, and Svelte to Next.js, Astro, TanStack Query, and more. Each section includes a quick intro, core features, and sample code to help you start fast. 🔗 Read the full article: https://lnkd.in/gH4i-gfG https://lnkd.in/gUMkaQHC