How to Build Your Own Custom Hooks in React

🚀 Understanding React Class Component Lifecycle In React, Class Components have a well-defined lifecycle — a sequence of methods that run during the component’s creation, update, and removal from the DOM. Knowing these lifecycle methods helps developers control how components behave and interact with data at each stage. 🔹 1. Mounting Phase – When the component is created and inserted into the DOM. ➡️ constructor() – Initializes state and binds methods. ➡️ render() – Returns JSX to display UI. ➡️ componentDidMount() – Invoked after the component mounts; ideal for API calls or setting up subscriptions. 🔹 2. Updating Phase – When props or state changes cause a re-render. ➡️ shouldComponentUpdate() – Decides if the component should re-render. ➡️ render() – Re-renders the updated UI. ➡️ componentDidUpdate() – Called after re-render; perfect for DOM updates or data fetching based on previous props/state. 🔹 3. Unmounting Phase – When the component is removed from the DOM. ➡️ componentWillUnmount() – Used to clean up (like removing event listeners or canceling API calls). 💡 Example: I recently implemented lifecycle methods in a project to fetch product data using componentDidMount() from a fake API(https://lnkd.in/gkFvXQV6) and dynamically display it on the UI. It helped me understand how React efficiently handles rendering and updates. 10000 Coders Meghana M #ReactJS #WebDevelopment #Frontend #Learning #ReactLifecycle #JavaScript #CodingJourney

 You think you know React... until you have to clean up a third-party script. I had a major "Aha!" moment building my Financial dashboard project, and it's a perfect example of how React's declarative world meets imperative, real-world JavaScript. The Problem: I'm integrating TradingView's embeddable widgets, which aren't React components. This requires manually creating <script> tags and injecting them into a div using a useEffect hook. The Naive Approach: Just create the script in useEffect and let React unmount the div when it's done. Simple, right? Wrong. This creates massive memory leaks. The third-party script (the "tenant") running inside my div (the "house") has its own background processes: setIntervals, WebSockets, and global event listeners. When React unmounts the div (demolishes the house), it doesn't tell the tenant to clean up. The "ghost" tenant lives on, still fetching data and consuming memory. The Solution & The "Aha!" Moments: 1. The "Stale Ref" Problem: My first attempt at a cleanup function failed because ref.current is null when the cleanup runs! The Fix: You have to snapshot the ref's value inside the effect: const node = ref.current;. The cleanup function's closure then remembers this node, even after ref.current is nullified. 2. The "Tenant Eviction" Model: This was the real lightbulb moment. Why clean the div with node.innerHTML = "" if React is removing it anyway? The Fix: The cleanup is not for React. It's a signal for the third-party script. Setting innerHTML = "" is like "evicting the tenant." The script is built to detect this, triggering its own internal destroy() logic—clearing its timers, closing its connections, and actually preventing the memory leak. Takeaway: React manages its own lifecycle, but we are 100% responsible for the lifecycle of any imperative, non-React code we introduce. This dive was a powerful lesson in JavaScript closures, React's lifecycle, and robust memory management. #reactjs #javascript #webdevelopment #frontend #MERNstack #reacthooks #memorymanagement #learning #coding

Ever felt like debugging a slow UI update was like pouring water into a basket? We’ve all been there. We write some JS code, change some state, and suddenly our UI is sluggish. We instinctively blame the browser's "slowness." But what's really happening under the hood? React handles rendering in a way that might surprise some developers. React does not have its own magical rendering engine. React is just JavaScript running in a browser's JS engine (V8, SpiderMonkey, and so on). Every render and commit phase runs in the main thread's call stack. So how does React make complex UIs feel fast if it’s just running JS? Here’s the secret: - The "Virtual DOM" Blueprint: When the state changes, React first builds a virtual copy of the new UI in pure JS (the render phase). This is fast, as it doesn't touch the actual browser UI. - The Diffing Strategy: React then compares the new blueprint to the old one. It finds the minimal changes required to sync reality with the blueprint. - The Browser Handshake: React talks to the real browser rendering engine via standard DOM APIs. The key takeaway? React doesn't re-render the entire DOM tree every time (which would be expensive). It calculates the exact elements that need updating. This efficiency is why React feels so performant. It’s intelligent DOM manipulation. Understanding this architecture helps write better, faster code. #ReactJS #FrontendDevelopment #JavaScript #WebDev #Engineering #CareerGrowth #TechInsights

⚛️ Understanding React Hooks: useMemo, useReducer, useCallback & Custom Hooks React Hooks make functional components more powerful and efficient. Here are four advanced hooks every React developer should know.. 🧠 1. useMemo Purpose: Optimizes performance by memoizing (remembering) the result of a computation. React re-renders components often useMemo prevents re-calculating expensive values unless dependencies change. Use it for: heavy calculations or filtered lists. ⚙️ 2. useReducer Purpose: Manages complex state logic more efficiently than useState. It works like a mini version of Redux inside your component — using a reducer function and actions. Use it for: forms, complex state transitions, or when multiple states depend on each other. 🔁 3. useCallback Purpose: Prevents unnecessary re-creations of functions during re-renders. It returns a memoized version of a callback function so it’s not recreated every time unless dependencies change. Use it for: optimizing child components that rely on reference equality. 🪄 4. Custom (User-Defined) Hooks Purpose: Reuse stateful logic across components. If you find yourself using the same logic in multiple places, you can create your own hook (e.g., useFetch, useLocalStorage, etc.). Use it for: fetching data, handling forms, authentication logic, etc. 🚀 These hooks help write cleaner, faster, and more maintainable React code. Understanding when and how to use them will make you a more efficient developer. #React #ReactJS #ReactHooks #useMemo #useReducer #useCallback #CustomHooks #FrontendDevelopment #FrontendEngineer #WebDevelopment #WebDeveloper #JavaScript #JS #ES6 #Programming #Coding #DeveloperCommunity #TechLearning #MERN #stemup

In React, why does changing the ref value not trigger multiple re-renders? Let's discuss what happens under the hood in React. 1. React initializes the ref object with initialValue defined in the code. 2. The ref object is saved in the memoizeState property of the hook node in the linked list of hooks. 3. The hooks linked list is internally managed by React with the order in which we define hooks in the component's code. 4. If useRef is the first hook, its data will get saved on memoizedState property of an internal structure called currentlyRenderingFiber which refers to the fiber node of the component currently being rendered. 5. Otherwise, the work-in-progress pointer will add useRef to the hooks linked list as per the order of the hooks in the code. 6. WorkInProgress is an internal pointer to traverse the hooks linked list, add a new hook during the first render, or reuse/clone existing ones during re-rendering. 7. React maintains hooks in a linked list so that the order of hooks doesn't get changed. When rerender happens 1. The React updateRef method is called internally, and the WorkInProgress pointer traverses through the hooks linked list, finds, and returns the same memoizedState node against which ref was initially defined. Points no. 4, 5, and 6 might feel quite overwhelming; I will discuss these in the coming days. I do a deep dive into foundational concepts & how things work under the hood. You can consider connecting with or following me, Ali Raza, to get along with the journey. #react #javascript #frontend #nextjs

Just learned how React Hooks simplify state management! I’ve been exploring React Hooks lately, and I’m amazed by how they replace complex class components with cleaner, functional code. Here are my key takeaways: 1️⃣ useState — Perfect for managing simple, local state. No need for class constructors or this.setState(). 2️⃣ useEffect — Helps handle side effects like API calls or event listeners — super useful for cleaner, lifecycle-like logic. 3️⃣ useContext — Makes sharing state across components easy without heavy libraries like Redux. 4️⃣ Custom Hooks — Great way to reuse logic (e.g., form validation, API fetching). Before hooks, I often found myself juggling multiple lifecycle methods or passing props too deeply. Now, with hooks, my components are smaller, cleaner, and easier to test. What’s your favorite React Hook or use case? #React #JavaScript #WebDevelopment #Frontend #ReactHooks #LearningInPublic

💡 A powerful (and often underrated) use case for useRef in React useRef isn’t just about accessing DOM elements — it quietly solves one of the most important problems in React: preserving mutable values across re-renders without triggering re-renders. A classic example is a stopwatch ⏱️ const timerRef = useRef(null); const start = () => { timerRef.current = setInterval(() => { setSeconds((s) => s + 1); }, 1000); }; const stop = () => { clearInterval(timerRef.current); }; If we used a normal variable like let timer, React would reset it to null after every re-render (since the component function runs again). The result? Your “Stop” button wouldn’t actually stop the timer — the interval would keep running in the background. useRef prevents that by giving you a stable place to store such values — perfect for things like: Intervals / timeouts WebSocket or media stream instances Storing previous values Keeping track of imperative API references It’s one of those hooks that doesn’t re-render the UI, but silently keeps your logic rock solid. ⚙️✨ Sometimes, the most powerful tools are the quiet ones. #ReactJS #FrontendDevelopment #WebDev #JavaScript #useRef

💭 Ever wished window.confirm() could show your own custom modal? I did — and got tired of juggling modal states, callbacks, and context just to ask: “Are you sure?” So I built a small helper for myself… and figured others might find it useful too 👇 👉 @sghere/react-confirm A minimal, promise-based confirm utility for React — lightweight, zero-config, and works beautifully with your own UI. ✨ Features 🧩 Zero configuration — works out of the box ⚛️ Fully compatible with React 16+ and 18 💬 Promise-based API: await confirm({...}) 🧠 Type-safe with ConfirmOptions support 🎨 Tailwind-ready styling — easily themeable 🪶 Lightweight — under 5 KB gzipped 📦 Installation npm install @sghere/react-confirm # or yarn add @sghere/react-confirm # or bun add @sghere/react-confirm ⚠️ Requires react and react-dom as peer dependencies 🚀 Quick Start import { confirm } from "@sghere/react-confirm"; import "@sghere/react-confirm/dist/react-confirm.css"; <button onClick={() => { confirm({ heading: "Are you sure?", body: "This will be deleted", onConfirm: () => { alert("Deleted ✅"); }, }); }} > Delete Item </button> It’s a small utility — nothing fancy — but it’s made my workflow cleaner and faster. If you give it a try, I’d love your thoughts or suggestions to make it better 🙌 #React #OpenSource #Frontend #JavaScript #ReactJS #WebDev #DeveloperTools #DevCommunity

🚀 Advanced React: Mastering Array Rendering & List Optimization As React developers, we often work with arrays and lists, but are we doing it efficiently? Here are some advanced techniques to level up your skills: ✅ 1. Always Use Unique Keys Never use array indices as keys for dynamic lists. Use unique IDs to help React optimize re-renders and avoid bugs when items are added/removed. ⚡ 2. Virtualization for Large Lists Rendering 10,000+ items? Use react-window or react-virtualized to render only visible items. This dramatically reduces DOM nodes and improves performance. 🎯 3. Map Function Best Practices The .map() method is your friend! Create dynamic UI components without repetitive code. Return JSX directly within map for cleaner code. 🔧 4. Pagination & Infinite Scroll For massive datasets, implement pagination or infinite scroll patterns. Load data in chunks as users scroll to maintain smooth performance. 💡 5. Memoization with React.memo Prevent unnecessary re-renders of list items by wrapping components with React.memo. Combine with useMemo for expensive computations. 📊 Example Pattern: const items = data.map((item) => (  <ListItem key={item.id} {...item} /> )); Remember: Performance optimization isn't premature optimization—it's smart development! #ReactJS #WebDevelopment #JavaScript #FrontendDevelopment #ReactOptimization #CodingTips #SoftwareEngineering #WebPerformance

💡React Tip💡 You don't need to use debouncing every time during search or filtering. React 18's useTransition hook offers a more seamless way to manage them. ⚡ 𝗪𝗵𝘆 𝗶𝘁'𝘀 𝗽𝗼𝘄𝗲𝗿𝗳𝘂𝗹: → Keeps your UI responsive during heavy updates → No need for setTimeout or debounce libraries → Built-in priority system for React rendering → Perfect for search filters, data tables, and complex lists 𝗧𝗵𝗲 𝗣𝗿𝗼𝗯𝗹𝗲𝗺: When filtering large lists, every keystroke can freeze your UI because React tries to update everything immediately. 𝗦𝗼𝗹𝘂𝘁𝗶𝗼𝗻: use useTransition hook from react. useTransition lets you mark certain updates as "low priority" so React can keep your UI smooth. In the code sample example, typing in the search box updates instantly (high priority), while filtering the huge list happens in the background (low priority) without blocking the input. The isPending flag tells you when the background work is still running, so you can show a loading indicator. 𝗞𝗲𝘆 𝗕𝗲𝗻𝗲𝗳𝗶𝘁𝘀: → Input stays responsive - no lag while typing → React automatically prioritizes user input over list updates → isPending gives you a loading state for free → Works seamlessly with Suspense boundaries 𝗖𝗵𝗲𝗰𝗸 𝗼𝘂𝘁 𝘁𝗵𝗲 𝗦𝘁𝗮𝗰𝗸𝗯𝗹𝗶𝘁𝘇 𝗱𝗲𝗺𝗼 𝗹𝗶𝗻𝗸 𝗶𝗻 𝘁𝗵𝗲 𝗰𝗼𝗺𝗺𝗲𝗻𝘁 𝘁𝗼 𝘀𝗲𝗲 𝗶𝘁 𝗶𝗻 𝗮𝗰𝘁𝗶𝗼𝗻. 𝘍𝘰𝘳 𝘮𝘰𝘳𝘦 𝘴𝘶𝘤𝘩 𝘶𝘴𝘦𝘧𝘶𝘭 𝘤𝘰𝘯𝘵𝘦𝘯𝘵, 𝘥𝘰𝘯'𝘵 𝘧𝘰𝘳𝘨𝘦𝘵 𝘵𝘰 𝘧𝘰𝘭𝘭𝘰𝘸 𝘮𝘦. #javascript #reactjs #nextjs #webdevelopment