React Mistake 1: Mutating State Directly

🚀 30 Days — 30 Coding Mistakes Beginners Make Day 18/30 I clicked “Add Item”… nothing happened 😐 No error. No warning. Button worked. My code: items.push("New Task") setItems(items) The array DID change. But React didn’t update UI. Why? Because React doesn’t check contents. React checks references. Same array reference = React thinks nothing changed. Fix 👇 setItems([...items, "New Task"]) Create a NEW array instead of modifying the old one. This single mistake causes many: “React state not updating” moments. Save this — you will hit this bug in a real project. #30DaysOfCode #reactjs #javascript #frontend #codeinuse

🚀 Why Do We Need Hooks in React? In traditional JavaScript, imagine we create a button that updates a number displayed in multiple places on the UI. Every time the button is clicked, we would have to: Select each element separately Get its reference Manually update the textContent for every element If that number appears in 4–5 places, we would need to update all of them individually. This process quickly becomes messy and inefficient. This is where React Hooks changed everything. With the useState Hook, we can manage a single piece of state and React automatically updates every place in the UI where that state is used. Instead of manually manipulating the DOM multiple times, we just update the state once — and React takes care of the rest. This simple idea is what made React extremely powerful and scalable. Even organizations like Khan Academy realized how efficient UI management becomes with React. ✨ One Hook. One State. Multiple UI Updates. That’s the power of React Hooks. #ReactJS #ReactHooks #FrontendDevelopment #JavaScript #WebDevelopment #LearningInPublic #SoftwareEngineering #ReactDeveloper #CodingJourney

One thing I often notice while learning and working with React is that many beginners only focus on the most common hooks like useState and useEffect. They see other hooks but usually just go through them quickly without understanding their real purpose. However, React provides many hooks and each of them solves a specific problem. Ignoring them means missing powerful tools that can make your code cleaner and more efficient. For example, instead of managing too many states inside a component with multiple useState calls, you can use useReducer to manage complex state logic in a more organized way. Similarly, useRef is very useful when you want to persist a value without causing a re-render or when you need to access a DOM element directly. For instance, you can use useRef to focus an input field automatically when a component loads. Hooks like useMemo and useCallback help optimize performance by preventing unnecessary calculations and function recreations in larger applications. And in routing scenarios, useNavigate makes navigation between pages simple and programmatic. The key point is: if you want to become strong in React, it's important not to just memorize hooks but to understand when and why they should be used. Once you start understanding the real use cases of these hooks, your code becomes more structured, efficient, and scalable. #React #WebDevelopment #FrontendDevelopment #JavaScript #ReactJS

⚠️ Master the language before jumping into frameworks I thought frameworks were the shortcut. I thought React, Next.js, and big tools would make me “look” like a real developer. But I was wrong. A framework does not fix weak fundamentals. It only exposes them. When you don’t understand JavaScript deeply: • You copy code without understanding • You fear debugging • You depend on tutorials • You feel stuck when errors appear But when you master the language first… Everything changes. Frameworks become easier. Documentation becomes clearer. Bugs become solvable. Confidence becomes natural. JavaScript is not “just a step.” It is the foundation. Variables. Scope. Functions. Arrays. Objects. Events. If these are strong, any framework becomes lighter. I’ve learned something important in my journey: Slow down. Understand the language. Then scale. Because building on weak foundation only creates bigger problems later. If you’re learning frontend development right now, don’t rush the framework hype. Master the language. Frameworks will wait. 💬 Be honest — did you jump into a framework too early, or did you take your time? #JavaScriptDeveloper #FrontendDevelopment #WebDevelopmentJourney #SoftwareEngineering #LearnToCode

⚡ 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

🚀 30 Days — 30 React Mistakes Beginners Make 📅 Day 2/30 ❌ Mistake: Using Index as Key in Lists My list UI started behaving strangely after deleting an item 😵 Code 👇 {users.map((user, index) => ( <div key={index}>{user.name}</div> ))} Looks fine… but it’s not. 💡 Why This Is a Problem React uses key to identify elements between renders. When items are added or removed: Index changes React reuses wrong elements UI bugs appear ✅ Correct Way {users.map((user) => ( <div key={user.id}>{user.name}</div> ))} Use a unique and stable key (like id). 🎯 Lesson Index as key = future bug. Stable keys = stable UI. #ReactJS #JavaScript #Frontend #WebDevelopment #CodingJourney #DeveloperLife #LearnToCode #ReactDeveloper #TechContent #CodeNewbie

One mistake I see many developers make is jumping into frameworks too early. Everyone wants to learn React, Next.js, or other modern tools because they are popular in the industry. But many people skip the most important step — building a strong JavaScript foundation. React is not magic. It is simply JavaScript with a different way of organizing code. If you don’t understand concepts like functions, array methods, async programming, event handling, or how JavaScript actually runs, React will feel confusing and frustrating. It’s like trying to read a novel in a language you don’t speak. Before learning React, focus on mastering JavaScript fundamentals: • Functions and arrow functions • Object and array manipulation • Map, filter, and reduce • Promises and async/await • Event handling • Error handling And most importantly — build small projects using Vanilla JavaScript. Because frameworks can make development faster, but fundamentals make you a better developer. 🚀 #javascript #reactjs #webdevelopment #frontenddevelopment #coding #softwaredeveloper #devcommunity #learncoding

Learning React made me realize something — frontend isn’t about “changing elements.” It’s about controlling state and thinking in systems. Once that clicked, everything started making sense. Still early in the journey, but the foundation is getting stronger every day. Next stop: advanced hooks and performance optimization. Building > consuming. #ReactJS #JavaScript #FrontendDeveloper #WebDevelopment #CodingJourney #LearnInPublic #FullStackPath

🚀 Day 1 to 5 of Learning React — Understanding JSX & Babel (Behind the Scenes) Today I explored how React actually works under the hood, and honestly… it’s pretty cool • What is JSX? JSX stands for JavaScript XML. It allows us to write HTML-like code inside JavaScript. Example: const element = <h1>Hello World</h1>; But here’s the catch Browsers don’t understand JSX directly • Role of Babel Babel is a transpiler that converts JSX into normal JavaScript. Above JSX becomes: React.createElement("h1", null, "Hello World"); So basically: • JSX → Babel → JavaScript → Browser • How React works behind the scenes React creates a Virtual DOM Instead of updating the real DOM directly (which is slow), React: 1. Creates a Virtual DOM (lightweight copy) 2. Compares changes (Diffing) 3. Updates only the changed parts (Reconciliation) • This makes React super fast Key Takeaway: React is not magic — it’s just smart optimization + JavaScript power. # Next: Diving deeper into Components & Hooks #ReactJS #WebDevelopment #JavaScript #LearningInPublic #Frontend #CodingJourney Vikas Kumar Prashant Pal Pratyush Mishra Prakash Sakari Likitha S Rajit Ram GeeksforGeeks

💡 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