React Lifecycle Methods Simplified: Mounting, Updating, Unmounting

𝟯 𝗧𝗿𝗶𝗰𝗸𝘆 𝗥𝗲𝗮𝗰𝘁 𝗜𝗻𝘁𝗲𝗿𝘃𝗶𝗲𝘄 𝗤𝘂𝗲𝘀𝘁𝗶𝗼𝗻𝘀 𝗔𝘀𝗸𝗲𝗱 𝗶𝗻 𝗠𝗮𝗻𝘆 𝗜𝗻𝘁𝗲𝗿𝘃𝗶𝗲𝘄𝘀 These are not your typical “what is useState” questions. These are the ones that actually test how well you understand React. ⸻ 1️⃣ Why does this component re-render even with React.memo? A child component is wrapped with React.memo. Props look the same. But it still re-renders. 👉 What could be causing this? Hint: Think beyond primitive values. ⸻ 2️⃣ Why is this useEffect running twice in development? You wrote an effect with an empty dependency array. Still, it runs twice. 👉 Is this a bug or expected behavior? 👉 What is React doing behind the scenes? ⸻ 3️⃣ Why is state not updating inside this async function? You update state, but inside a setTimeout or async callback, it still uses the old value. 👉 Why does this happen? 👉 How would you fix it? ⸻ These questions are simple to read… But tricky to answer correctly. Day 19/100 — sharing real React interview questions. #ReactJS #FrontendInterviews #JavaScript #FrontendEngineering #TechCareers

Most important question that was asked in React Developer interview Sharing the questions here in case it helps someone preparing for similar roles. Some of the questions they asked: 1. What is React and why is it efficient? 2. How does React work internally? 3. What is the most challenging task you handled in your project? 4. Is JavaScript tightly coupled or loosely coupled? 5. Why do we use TypeScript? 6. How does "extends" work in TypeScript and what is the difference between type and interface? 7. How does Redux work, from installation to usage in a project? 8. Have you used Redux Toolkit (RTK) or TanStack Query? 9. What is the difference between bind and apply in JavaScript? 10. What has been your experience with useCallback and useMemo in real projects? 11. What is the role of the dependency array in useEffect? Overall, the round was focused on practical understanding of React, TypeScript and JavaScript rather than just theory. 👨💻 Follow for daily React, and JavaScript #React #JavaScript #TypeScript #Redux #Frontend #InterviewExperience #capgemini

🚀 𝗦𝘁𝗼𝗽 𝗚𝗼𝗼𝗴𝗹𝗶𝗻𝗴 𝗥𝗲𝗮𝗰𝘁 𝘀𝘆𝗻𝘁𝗮𝘅 𝗮𝗴𝗮𝗶𝗻 𝗮𝗻𝗱 𝗮𝗴𝗮𝗶𝗻... What if you had everything in one place? 👇 I’ve created a React.js Cheat Sheet to help you build faster and code smarter ⚛️ 📚 What’s inside: • JSX fundamentals • Core React concepts • Essential Hooks (useState, useEffect & more) 💡 Who is this for? ✔ Beginners getting started with React ✔ Developers preparing for interviews ✔ Engineers who want faster development & cleaner code 📌 Pro Tip: Great developers don’t memorize everything… They build systems and references they can rely on 💾 Save this post so you don’t have to search again while building 💬 Let’s discuss: What was the most confusing React concept when you started? 👨💻 Follow for more dev content #ReactJS #FrontendDevelopment #WebDevelopment #JavaScript #ReactHooks #CodingLife #DevTips #SoftwareEngineering

🚀 Stop Googling React syntax again and again… What if you had everything in one place? 👇 I created a React.js Cheat Sheet to help you build faster and code smarter 📚 What’s inside: • JSX fundamentals • Core concepts of React.js • Essential Hooks (useState, useEffect & more) 💡 Who is this for? ✔ Beginners starting with React ✔ Developers preparing for interviews ✔ Engineers who want faster development & cleaner code 📌 Pro Tip: Great developers don’t memorize everything… They create systems & references they can rely on. 💾 Save this post so you don’t have to search again while building 💬 Let’s discuss: What was the most confusing React concept for you when you started? Follow M. WASEEM ♾️ for more valuable content #ReactJS #FrontendDevelopment #WebDevelopment #JavaScript #ReactHooks #CodingLife #DevTips

Great developers don’t try to remember everything. They build systems that remember for them. A cheat sheet isn’t a shortcut— it’s a smart way to move faster.

𝟯 𝗧𝗿𝗶𝗰𝗸𝘆 𝗥𝗲𝗮𝗰𝘁 𝗜𝗻𝘁𝗲𝗿𝘃𝗶𝗲𝘄 𝗤𝘂𝗲𝘀𝘁𝗶𝗼𝗻𝘀 𝗔𝘀𝗸𝗲𝗱 𝗶𝗻 𝗠𝗮𝗻𝘆 𝗜𝗻𝘁𝗲𝗿𝘃𝗶𝗲𝘄𝘀 These are not your typical “what is useState” questions. These are the ones that actually test how well you understand React. ⸻ 1️⃣ Why does this component re-render even with React.memo? A child component is wrapped with React.memo. Props look the same. But it still re-renders. 👉 What could be causing this? Hint: Think beyond primitive values. ⸻ 2️⃣ Why is this useEffect running twice in development? You wrote an effect with an empty dependency array. Still, it runs twice. 👉 Is this a bug or expected behavior? 👉 What is React doing behind the scenes? ⸻ 3️⃣ Why is state not updating inside this async function? You update state, but inside a setTimeout or async callback, it still uses the old value. 👉 Why does this happen? 👉 How would you fix it? ⸻ These questions are simple to read… But tricky to answer correctly. #ReactJS #FrontendInterviews #JavaScript #FrontendEngineering #TechCareers

🚀🔥 The Ultimate React JS Cheat Sheet Every Developer Needs in 2026 Struggling to remember all React concepts during interviews or while building projects? 🤯 Here’s a power-packed React JS Cheat Sheet that puts everything in one place — from basics to advanced topics — so you can code faster and smarter 🚀 Mastering React becomes easier when you have the right concepts at your fingertips. Here’s a quick cheat sheet to boost your productivity and quick guide will help you revise, build, and crack interviews with confidence 💯👇 💡 Pro Tip: Don’t just read—build projects using these concepts to truly master React! 📌 Save this post & follow for more developer-friendly content #ReactJS #FrontendDevelopment #JavaScript #WebDevelopment #ReactHooks #Coding #SoftwareEngineering #UIDevelopment

Stop using 𝗮𝗻𝘆 in TypeScript 🚀 The whole point of TypeScript is to bring type safety to JavaScript. So when I still see any in codebases, PRs, or interviews — it’s usually a 🔴 red flag. Yes, TypeScript provides 𝗮𝗻𝘆 for edge cases. But let’s be honest… most of the time, it’s used to silence the compiler instead of fixing the problem. (PS: Hey compiler, shut the hell up and ignore my mistake 😅) And when you do that, you’re essentially opting out of everything TypeScript is trying to help you with. You’re not “𝙬𝙤𝙧𝙠𝙞𝙣𝙜 𝙬𝙞𝙩𝙝 𝙏𝙮𝙥𝙚𝙎𝙘𝙧𝙞𝙥𝙩” anymore — you’re just writing JavaScript with extra steps 😅 Instead, try: → unknown when the type isn’t clear yet → proper interfaces or generics → narrowing with type guards TypeScript is at its best when you let it guide you — not when you bypass it. Use any as a last resort, not a default. If you found this resourceful, please follow Aslam Mohammed and feel free to share your thoughts 👇 #JavaScript #TypeScript #WebDevelopment #Frontend #InterviewQuestions #TypeScriptInterviewQuestions #JuniorDeveloper

𝐖𝐡𝐲 𝐃𝐨 𝐖𝐞 𝐔𝐬𝐞 𝐂𝐥𝐨𝐬𝐮𝐫𝐞𝐬 𝐢𝐧 𝐑𝐞𝐚𝐜𝐭 𝐉𝐒? 🤔 Closures are one of the most important concepts in JavaScript… and React uses them everywhere. But many developers don’t realize it 👇 What is a closure? A closure is when a function remembers the variables from its outer scope even after that scope has finished execution. How React uses closures 👇 🔹 Event Handlers Functions like onClick capture state values at the time they are created 🔹 Hooks (useState, useEffect) Hooks rely on closures to access state and props inside functions 🔹 Async operations (setTimeout, API calls) Closures hold the state values when the async function was created Example 👇 const [count, setCount] = useState(0); const handleClick = () => { setTimeout(() => { console.log(count); }, 1000); }; What will this log? 🤔 It logs the value of count at the time handleClick was created This is why we sometimes face “stale closure” issues ⚠️ Why this matters? Understanding closures helps you: ✔ Debug tricky bugs ✔ Avoid stale state issues ✔ Write better React logic Tip for Interview ⚠️ Don’t just define closures Explain how they behave in React That’s what interviewers look for Good developers use React. Great developers understand how it works under the hood. 🚀 #ReactJS #JavaScript #Closures #FrontendDeveloper #WebDevelopment #ReactInterview #CodingInterview #SoftwareDeveloper

𝐑𝐞𝐚𝐜𝐭 𝐮𝐬𝐞𝐄𝐟𝐟𝐞𝐜𝐭 𝐈𝐧𝐭𝐞𝐫𝐯𝐢𝐞𝐰 𝐐𝐮𝐞𝐬𝐭𝐢𝐨𝐧 🤔 Many developers use useEffect daily… but fail to answer this. Question: What happens if dependency array is empty in useEffect? Example: useEffect(() => { console.log("Hello"); }, []); Answer 👇 When dependency array is empty [] ➡ useEffect runs only once ➡ It runs after first render ➡ It will NOT run again on state change Why? Because React thinks there are no dependencies to watch. Now tricky part ⚠️ useEffect(() => { console.log(count); }, []); If count changes, this will NOT run again. Because count is not in dependency array. Correct way ✅ useEffect(() => { console.log(count); }, [count]); Tip for React Interviews: Always remember — No dependency → runs every render Empty array → runs once With dependency → runs when value changes More React interview questions coming 🚀 #ReactJS #useEffect #FrontendDeveloper #JavaScript #WebDevelopment #CodingInterview #ReactInterview #NextJS #SoftwareDeveloper