What is a Closure in JavaScript

🚀 6 React Hooks that changed how I write code — and will change yours too. If you're still confused about when to use what, here's the simplest breakdown: 🔵 useState → Store & update values. Every re-render starts here. 🌐 useEffect → Talk to the outside world (APIs, DOM, subscriptions). 📦 useRef → Hold a value WITHOUT triggering a re-render. A hidden drawer for your data. 🧠 useCallback → Memoize functions so they don't get recreated on every render. ⚡ useMemo → Cache expensive calculations. Only recompute when dependencies change. 🌍 useContext → Share state globally. No more prop drilling through 5 layers. The moment these clicked for me, my components became cleaner, faster, and way easier to debug. Which hook took you the longest to truly understand? Drop it in the comments 👇 #ReactJS #WebDevelopment #JavaScript #Frontend #Programming #React #SoftwareEngineering #100DaysOfCode #CodeNewbie #TechEducation #FrontendDeveloper #ReactHooks

When I first heard "JavaScript is single-threaded," I thought it was a flaw someone was apologizing for. It's not. It's the most important thing to understand about the language. Single-threaded means JS can only do one thing at a time. One line runs, finishes, then the next begins. This makes JS behavior completely predictable - you always know the order things happen, with no two threads fighting over the same variable. The difficulty of async code doesn't come from JS doing multiple things at once. It comes from JS waiting while the browser does work in the background, and needing a controlled way to let that result back in. Once I understood this, async stopped feeling like black magic and started making sense. Next post: what actually happens when a function runs - the call stack. #JavaScript #WebDevelopment #Programming #SoftwareEngineering

I recently took some time to deeply understand three core JavaScript concepts that often confuse developers: Scope, Hoisting, and Closures. Instead of just memorizing, I wanted to truly understand how and why they work — so I broke everything down with simple explanations and practical examples. 📌 In this article, I covered: The real meaning of Scope (Global, Function, Block, Lexical) What actually happens during Hoisting How Closures work and why they’re so powerful in JavaScript I also connected all three concepts together — because once you see how they relate, things become much clearer 🔥 🔗 Check out the full article: https://lnkd.in/gT6dmXr3 I’d really appreciate your feedback and thoughts 🙌 #javascript #webdevelopment #frontend #programming #closure #hoisting #scope #developers

🔥 JavaScript Tip That Changed How I Write Code Hey devs 👋 At some point, I realized… 👉 Most bugs were not because of logic… They were because of “unexpected values” Things like: ❌ undefined ❌ null ❌ NaN 💡 Example: const price = undefined; price + 10 // NaN 😬 💡 What I started doing: ✔ Defensive programming ✔ Optional chaining (?.) ✔ Nullish coalescing (??) Example: const total = price ?? 0; ⚡ Lesson: JavaScript is flexible… but that flexibility can break your app. 👉 Rule: “Always expect the unexpected.” What’s the weirdest JS bug you’ve faced? #javascript #webdevelopment #programming #frontend #backend #softwareengineering #Coding #TechCareers #Programming #success

🔥 Let’s talk about something we all “know”… but rarely truly understand: The JavaScript Event Loop. Quick question 👇 Have you ever written async code… but your app still felt blocked? 👉 Here’s why: JavaScript runs on a single thread. So if you do this: while(true) {} 💥 Everything stops: UI freezes Promises don’t resolve API calls get delayed 💡 The reality: Async helps with I/O… not CPU work. ⚡ What changed my thinking: “If the main thread is busy, nothing else matters.” 👉 What I do now: ✔ Break heavy tasks into chunks ✔ Avoid long synchronous loops ✔ Use workers when needed Once you truly understand the event loop… debugging becomes 10x easier. What was your biggest “event loop moment”? 😄 #javascript #eventloop #webdevelopment #performance #programming #frontend #backend #softwareengineering #Coding #TechCareers

𝐓𝐡𝐞 𝐜𝐚𝐥𝐥 𝐬𝐭𝐚𝐜𝐤 𝐡𝐚𝐬 𝐧𝐨 𝐩𝐚𝐭𝐢𝐞𝐧𝐜𝐞. 𝐈𝐭 𝐞𝐱𝐞𝐜𝐮𝐭𝐞𝐬 𝐞𝐯𝐞𝐫𝐲𝐭𝐡𝐢𝐧𝐠 — 𝐢𝐧𝐬𝐭𝐚𝐧𝐭𝐥𝐲, 𝐫𝐮𝐭𝐡𝐥𝐞𝐬𝐬𝐥𝐲, 𝐢𝐧 𝐨𝐫𝐝𝐞𝐫. So what happens when you need a 𝐝𝐞𝐥𝐚𝐲? That's where I hit a wall. If JavaScript is single-threaded and the call stack never pauses — how does '𝐬𝐞𝐭𝐓𝐢𝐦𝐞𝐨𝐮𝐭' even work? Turns out, it doesn't live in JavaScript at all. 𝐖𝐞𝐛 𝐀𝐏𝐈𝐬 — 𝐬𝐞𝐭𝐓𝐢𝐦𝐞𝐨𝐮𝐭, 𝐟𝐞𝐭𝐜𝐡( ), 𝐃𝐎𝐌 𝐞𝐯𝐞𝐧𝐭𝐬, 𝐥𝐨𝐜𝐚𝐥𝐒𝐭𝐨𝐫𝐚𝐠𝐞 — are gifts from the browser, not the language. The browser quietly hands them off, runs them in the background, then places the result into a 𝐂𝐚𝐥𝐥𝐛𝐚𝐜𝐤 𝐐𝐮𝐞𝐮𝐞 . And here's the elegant part: The 𝐄𝐯𝐞𝐧𝐭 𝐋𝐨𝐨𝐩 sits there, watching. The moment the call stack is empty, it picks up the waiting callback functions and pushes it in. That's it. No magic. Just a disciplined handoff between three moving parts. JavaScript doesn't wait — but the browser builds the patience "around" it. 𝐓𝐚𝐤𝐞𝐚𝐰𝐚𝐲𝐬 : → 𝐓𝐡𝐞 𝐜𝐚𝐥𝐥 𝐬𝐭𝐚𝐜𝐤 𝐞𝐱𝐞𝐜𝐮𝐭𝐞𝐬 𝐟𝐚𝐬𝐭. 𝐍𝐞𝐯𝐞𝐫 𝐚𝐬𝐬𝐮𝐦𝐞 𝐢𝐭 𝐰𝐚𝐢𝐭𝐬. → 𝐖𝐞𝐛 𝐀𝐏𝐈𝐬 𝐚𝐫𝐞 𝐛𝐫𝐨𝐰𝐬𝐞𝐫-𝐩𝐨𝐰𝐞𝐫𝐞𝐝, 𝐚𝐜𝐜𝐞𝐬𝐬𝐞𝐝 𝐯𝐢𝐚 𝐭𝐡𝐞 𝐠𝐥𝐨𝐛𝐚𝐥 "𝐰𝐢𝐧𝐝𝐨𝐰" 𝐨𝐛𝐣𝐞𝐜𝐭. → 𝐓𝐡𝐞 𝐞𝐯𝐞𝐧𝐭 𝐥𝐨𝐨𝐩 𝐨𝐧𝐥𝐲 𝐚𝐜𝐭𝐬 𝐰𝐡𝐞𝐧 𝐭𝐡𝐞 𝐜𝐚𝐥𝐥 𝐬𝐭𝐚𝐜𝐤 𝐢𝐬 𝐜𝐥𝐞𝐚𝐫. #JavaScript #SoftwareEngineering #DeveloperJourney #LearningInPublic #Programming #TechCommunity #WebDevelopment

I spent 2 hours debugging my React code today. The problem? I forgot to add a key prop inside .map() 2 hours. Gone. We always check the big things first — API calls, state management, component logic... But the bug is always something embarrassing Here are 3 mistakes I make almost every week — ❌ Forgetting key prop in .map() ❌ Calling setState and expecting instant update ❌ Spending 1 hour on a bug that console.log solves in 2 minutes 3 years of experience and I still do this Tell me your most embarrassing bug in the comments 👇 I promise I won't judge. We have ALL been there. #reactjs #javascript #frontenddeveloper #webdevelopment #coding #100daysofcode #programminghumor

Every function you call in JavaScript gets pushed onto a structure called the call stack. That's how JS knows where to go back. Whatever sits on top of the stack is where execution is right now. When the function returns, it gets popped off - and the item below it is back on top, telling JS exactly where to return to. Without this, calling a function from the middle of another function would leave JS completely lost. There would be no "go back to where you were." One side effect: the call stack has limited space. If a function calls itself infinitely with no stopping condition, you get a stack overflow. The name makes perfect sense once you know what it actually is. Next: JS borrows the browser's timer and network - but the browser doesn't hand results back through the call stack. How does it communicate? #JavaScript #WebDevelopment #Programming #SoftwareEngineering

TypeScript 7.0 Beta just dropped and this is NOT a regular version bump 🔥 The entire compiler has been rewritten from JavaScript → Go. The result? \~10x faster builds. That's not a typo. Here's what you need to know: → The compiler now runs parsing, type-checking, and emitting in parallel → New --checkers flag lets you control how many type-checker workers spin up \(default: 4\) → New --builders flag parallelizes project reference builds — huge for monorepos → strict is now true by default \(finally!\) → target: es5 and moduleResolution: node are gone for good → You install it via @typescript/native-preview@beta and use tsgo instead of tsc Think of it like this — your old TypeScript compiler was a single chef cooking a 10-course meal one dish at a time. TS7 is a kitchen with 4 chefs working simultaneously, each handling different courses 🍳 The best part? It's not a rewrite from scratch. They methodically ported the existing codebase to Go, so the type-checking logic is structurally identical to TS 6.0. Same rules, way faster engine. Companies like Bloomberg, Canva, Figma, Google, Vercel, and Notion have already been testing it on multi-million line codebases. Beta label, but production-ready confidence. VS Code extension is already out too. The stable release is expected within 2 months. If you haven't tried it yet — now's the time 🚀 What's the first thing you'd test TS7 on — your main codebase or a side project first? #TypeScript #TypeScript7 #WebDev #JavaScript #Programming #GoLang #DevTools

Confused between var, let, and const? Here's all you need to know. 👇 Most JavaScript developers use all three — but few know exactly when and why. Here's a quick breakdown: ⚠️ var → Function-scoped, hoists as undefined, can be re-declared. Avoid it in modern code. 🔁 let → Block-scoped, re-assignable. Use it when values change. 🔒 const → Block-scoped, immutable binding. Your default choice. 💡 TDZ (Temporal Dead Zone) — let and const are hoisted but can't be accessed before their declaration line. That's a feature, not a bug. 💥One rule of thumb: Always start with const. Switch to let only when you need to reassign. Never touch var. Save this for your next code review. 🔖 #JavaScript #WebDevelopment #Frontend #JS #Programming #100DaysOfCode #CodeTips #SoftwareEngineering