React JS Handwritten Notes for Quick Learning

Remove Duplicates from an Array in JavaScript - 3 Smart Ways! How do you remove duplicates from an array ? Here are 3 different ways to solve it Method 1: Using Set (The One-Liner Magic) Method 2: Using a Loop (The Classic Approach) Method 3: Using filter() (The Elegant Approach) Why? The Set object automatically removes duplicates, making it the easiest and fastest method. Why? This is a fundamental approach interviewers may expect if they want you to avoid built-in methods. Why? This method leverages filter() to retain only the first occurrence of each element, making it clean and efficient. #100daysofreactprojects #javascriptreactquestion #MERNStack #javascriptchallenge #ReactJS #codingtips #developer #bootstrap #programmer #nodejs #nextjs #MERN #RTK #ReactJS

One common issue in async JavaScript is repetitive try/catch blocks that make code messy and harder to maintain. A cleaner approach is the await-to pattern, which wraps promises and returns [error, data]. This keeps your async functions clean, readable, and easier to debug. ✅ No nested try/catch ✅ No swallowed errors ✅ Cleaner and reusable code ✅ Better error handling pattern Sometimes the best optimization is not adding more code — it’s removing repetition. What pattern do you use for handling async errors in your projects? #JavaScript #ReactNative #NodeJS #CleanCode #AsyncAwait #SoftwareDevelopment #WebDevelopment

🚨 JavaScript myth alert: Most devs think the spread operator (...) is always safe. But here’s the catch 👉 it only makes a shallow copy. That means: ✅ Flat objects → fine ❌ Nested objects → still linked by reference And that’s how sneaky bugs creep into your React state, Angular forms, or API transformations. 💡 Quick challenge for you: Have you ever seen { ...obj } cause unexpected behavior in your code? 🛠️ Pro tip: Use structuredClone for deep copies, or a custom recursive function if you want to show off your fundamentals. 🔥 Don’t just memorize syntax. Understand how JavaScript handles memory & references — that’s what makes you a stronger developer. #JavaScript #Frontend #ReactJS #Angular #WebDevelopment #CodingTips #DevLife

⚡ Most developers accidentally make async JavaScript slower than it needs to be. A lot of people write async code like this: await first request wait… await second request wait… await third request It works. But if those requests are independent, you’re wasting time. The better approach: ✅ run them in parallel with Promise.all() That small change can make your code feel much faster without changing the feature at all. Simple rule: If task B depends on task A → use sequential await If tasks are independent → use Promise.all() This is one of those JavaScript habits that instantly makes you look more senior 👀 Join 3,000+ developers on my Substack: 👉 https://lnkd.in/dTdunXEJ How often do you see this mistake in real codebases? #JavaScript #WebDevelopment #Frontend #SoftwareEngineering #AsyncJavaScript #Promises #CodingTips #Developers #LearnToCode #AITechDaily

Many beginners think React and JSX are the same, but they are actually different concepts. 🔹 React React is a JavaScript library used to build user interfaces, especially for single-page applications (SPAs). It helps developers create reusable components and manage UI efficiently. 🔹 JSX (JavaScript XML) JSX is a syntax extension for JavaScript used in React. It allows you to write HTML-like code inside JavaScript, making UI code easier to read and write. ✨ In short: React builds the UI, and JSX makes writing that UI easier. If you're learning React development, understanding JSX is the first step toward writing clean and scalable UI code. Nishant Pal #React #JSX #WebDevelopment #FrontendDevelopment #JavaScript #Coding

💡 Before React. Before Node. Before fancy frameworks. There is HTML, CSS, and JavaScript. And honestly? Most bugs I’ve seen in projects come from weak fundamentals — not advanced concepts. Here’s what strong basics actually mean: 🔹 HTML Understanding semantic tags, accessibility, proper structure. 🔹 CSS Knowing flexbox, positioning, box model, responsiveness — not just copying styles. 🔹 JavaScript Understanding closures, async/await, event loop, array methods — not just syntax. Frameworks change. Fundamentals don’t. The stronger your basics, the easier React, Node, or any tech becomes. Every time I improve my JS fundamentals, my React code improves automatically. #WebDevelopment #JavaScript #FrontendDeveloper #ReactJS #FullStackDeveloper #SheryiansCodingSchool

🚀 Tired of Googling JavaScript syntax every 5 mins? I got you. Here's an Interactive JavaScript Cheatsheet — and it slaps. 🧠 No more flipping through docs ⚡️ Fast, searchable, and clean 🛠️ Covers ES6+, DOM, array/object methods, async/await & more 🌙 Dark mode ready ✅ Copy-paste code blocks 📱 Mobile-friendly (because yes, we debug on phones too) If it helps you code faster, share it with a friend or teammate! Follow Muhammad Nouman for more useful content #JavaScript #WebDevelopment #Frontend #CodingLife #DevTools #ReactJS #NodeJS #WomenWhoCode #100DaysOfCode #CodeNewbie #DeveloperTools #JavaScriptCheatsheet #BuildInPublic #TechForGood

🚨 Still confused about React lifecycle methods? Complete Lifecycle Flow (Class Component) constructor() You’re not alone. When I first learned React, lifecycle methods felt like a mess: ❌ Too many methods ❌ Hard to remember order ❌ No clear real-world connection Then I realized one simple thing 👇 👉 React lifecycle is just 3 phases: ✔ Mounting (Component created) ✔ Updating (State/Props change) ✔ Unmounting (Component removed) That’s it. Once you understand this flow, everything starts making sense: 💡 When to call APIs 💡 Where to optimize performance 💡 How to avoid bugs So I created a simple visual to make it easy for anyone preparing for interviews or working on real projects. 📌 Save this for quick revision 📌 Share with your developer friends And tell me in the comments 👇 Which React topic should I simplify next? #ReactJS #FrontendDeveloper #FullStackDeveloper #JavaScript #WebDevelopment #Coding #InterviewPrep #TechCommunity

🚀 New Blog Alert for JavaScript Developers! Understanding this in JavaScript can feel like magic — until you truly get how call(), apply(), and bind() work. In this article, I break down these powerful concepts with simple explanations and practical examples you can actually use in real projects. 💡 👉 Read here: https://lnkd.in/dzxnYAqM If you’re learning JavaScript or preparing for interviews, this is a must-read! 🔥 Feedback and discussions are welcome 🙌 #JavaScript #WebDevelopment #Frontend #Coding #100DaysOfCode #LearnToCode

🚀 30 Days — 30 Coding Mistakes Beginners Make Day 17/30 I wrote an API call inside `useEffect`… and React showed a warning 😐 useEffect(async () => { const res = await fetch("/api/users") }, []) The mistake: `useEffect` should NOT be async. React expects the effect to return either: nothing, or a cleanup function. But async always returns a Promise. Fix 👇 Create an async function INSIDE the effect and call it. useEffect(() => { async function fetchUsers() { ... } fetchUsers() }, []) Small change. Correct lifecycle behavior. Day 18 tomorrow 👀 #30DaysOfCode #reactjs #javascript #frontend #webdevelopment