React State Update Delay Explained

Re-render misconception Most devs think: React re-renders = React re-paints the whole DOM. Not true - React re-renders components - then compares Virtual DOM - updates only what changed in real DOM So re-render ≠ performance problem. Performance problem happens when: heavy computations run on each render unnecessary re-renders trigger expensive children Fix: useMemo, useCallback, React.memo split components properly Question: what was the biggest re-render performance issue you faced in React? #reactjs #javascript #frontend #webdevelopment #performance

Most React bugs are not caused by React itself. They’re caused by how we think about components 🧠 Many developers treat components like “pages”. But React components are closer to pure functions: - UI = f (state, props) Here’s the practical rule I use 👇 If a component: - does more than one job - owns state it doesn’t really need - re-renders without a clear reason it’s usually a mental model problem, not a React one... React isn’t magic. It’s discipline in disguise. What React concept changed the way you write components? #React #Frontend #WebDevelopment #JavaScript #CleanCode

🚀 Understanding the React.js Reconciliation Process I’ve refined this visual to show how React efficiently updates the UI by comparing the Virtual DOM with the Real DOM. React’s Reconciliation algorithm works in two key steps: 🔹 Diffing – Detects what has changed between renders 🔹 Updating – Applies only the necessary changes to the Real DOM This is what makes React fast, efficient, and smooth when building dynamic user interfaces. If you’re learning React, mastering this concept helps you understand: ✔ Why re-renders happen ✔ How React minimizes DOM operations ✔ How performance is optimized behind the scenes A small concept — but a big performance win 💡 #ReactJS #FrontendDevelopment #WebDevelopment #JavaScript #Reconciliation #VirtualDOM #RealDOM #UIDevelopment #LearningReact

Why useEffect runs twice in React (and it’s NOT a bug) 👇 In development mode, React intentionally runs effects twice to help you: • detect side effects • enforce cleanups • avoid hidden bugs In production, it runs once. Fighting React here usually means misunderstanding React. Have you ever been confused by this behavior? #ReactJS #JavaScript #Frontend #WebDev #ReactHooks #TechLearning

Understanding stale closures in React took me longer than I expected. While working with useEffect, I ran into a situation where my code was using outdated state values. Everything looked correct at first, but the behavior wasn’t. This pushed me to really understand: how closures work in React why useEffect “sees” the world as it was when it was created when useRef is the right solution (and when it’s not) I wrote a blog post with real examples and trade-offs based on what I learned: 👉 [https://lnkd.in/dudVcZdM #React #JavaScript #NextJS #Frontend #WebDevelopment

🧠 Memory Flip Game using React & Vite — A Hands-On UI Practice Project 😊 Built using React + Vite to refine state handling, component structure, and UI interactions. With 1 year of hands-on React experience, I believe continuous building is the best way to stay sharp. #ReactJS #Vite #FrontendDevelopment #JavaScript #ReactProjects #BuildInPublic #FullStackDeveloper

🚀 Day 17 | React.js Topic: Props Post:Passing Data in React Today, I learned how props work in React and how they help components communicate with each other. Props allow data to flow from parent to child components, making UI blocks dynamic, reusable, and easy to manage.Understanding props is a key step toward building scalable and well-structured React applications. #ReactJS #ReactProps #FrontendDevelopment #JavaScript #WebDevelopment #MERNStack #LearningInPublic #ReactDeveloper #UIComponents #CodeJourney #TechLearning #ModernWeb #DeveloperLife

🔐 Password Generator using React.js 🚀 Just built a Password Generator using React.js while practicing core React hooks 💻✨ 🔧 What I used: useState → to manage password length & options useCallback → to optimize password generation Conditional logic → numbers & characters toggle 🎯 What this project taught me: Better understanding of state management How useCallback improves performance Writing cleaner & reusable logic Small projects like this make React concepts much clearer 🔥 Next step: adding copy-to-clipboard & UI improvements 🚀 #ReactJS #JavaScript #WebDevelopment #FrontendDeveloper #LearningReact #ReactHooks #PasswordGenerator #100DaysOfCode

If working with React, useEffect is one of the most important hooks must understand. 🔹What is useEffect? useEffect runs side effects in functional components things like: - Fetching data from an API. - Updating the DOM. - Subscribing/unsubscribing to events. - Timers, intervals, and more. 🔹Why useEffect matters? - Keeps UI in sync with data. - Prevents unnecessary re-renders. - Helps write cleaner, more predictable React code. 🔹When should this effect run? That answer defines the dependency array. 🔹It is very important to cleanup to avoid memory leaks. If you’re learning React or preparing for frontend interviews, mastering useEffect is a must. #ReactJS #JavaScript #WebDevelopment #Frontend #ReactHooks #LearningInPublic #CodingTips

Today I finally understood how React works behind the scenes, and it made everything click: 🔹 Virtual DOM keeps a lightweight UI copy 🔹 Reconciliation compares changes efficiently 🔹 Fiber schedules and prioritizes rendering work 🔹 React DOM updates only the required parts of the real DOM 📌 Key takeaway: React doesn’t re-render the whole page — it calculates minimal changes and updates only what’s needed, making apps fast and smooth. Understanding the fundamentals makes React feel less like magic and more like logic 💙 #ReactJS #FrontendDevelopment #LearningInPublic #JavaScript #Hitesh Choudhary