React State vs Props: Understanding the Basics for Frontend Interviews

React.js Interview Prep Mode ON! Today, I focused on one of the most commonly asked interview topics in React Props vs State Let’s break it down with a simple coding example import React, { useState } from "react"; // Child Component function CounterDisplay(props) { return <h2>Count: {props.count}</h2>; } // Parent Component function CounterApp() { const [count, setCount] = useState(0); return ( <div> <CounterDisplay count={count} /> <button onClick={() => setCount(count + 1)}> Increment </button> </div> ); } export default CounterApp; Interview Insights: - Props → Read-only, passed from parent to child - State → Managed inside component, can change over time - useState Hook → Most important hook for managing state in functional components Most Asked Interview Questions: - Difference between Props and State? - Can we modify props inside a component? ( No) - When to use state vs props? Key Takeaway: Understanding data flow (Unidirectional Flow) is to cracking React interviews. Consistency + Interview Focus = Selection #ReactJS #FrontendDevelopment #InterviewPreparation #100DaysOfCode #JavaScript #WebDevelopment

❓ React Interview Question: Difference between State and Props? 💡 What are Props? Props are inputs passed from parent to child components - They are read-only (immutable) - Used to make components reusable function Greeting(props) { return <h1>Hello {props.name}</h1>; } 💡 What is State? State is data managed inside a component - It can change over time (mutable) - Used for dynamic UI updates const [count, setCount] = useState(0); 💡 Key Differences props → Passed from parent, cannot be modified state → Managed inside component, can be updated props → Used for communication between components state → Used for handling dynamic data Follow Tarun Kumar for tech content, coding tips, and interview prep 🚀 #ReactJS #ReactInterview #FrontendInterview #JavaScript #CodingInterview #InterviewPrep #WebDevelopment #Developers #TechContent

Just spent some time preparing for React interviews on bfe.dev - and wow, it’s a goldmine. The platform is full of challenges that really make you think about core frontend concepts: -state management patterns -async behavior and the event loop -rendering and performance gotchas -hooks and reactivity -edge cases you actually encounter in real projects It’s not just about solving tasks - it’s about understanding why things work the way they do. After practicing consistently, I’ve noticed that tricky hook questions or performance scenarios become way easier to reason through. Curious to hear from you all - what are your go-to platforms for prepping for frontend interviews? #reactjs #frontend #javascript #webdevelopment #interviewprep

🚀 Just Built Something Powerful for React Interview Prep! I noticed most React interview prep content is either too basic or repetitive… so I decided to fix that. I’ve created a PDF with 30 unique React.js output-based questions that actually test real understanding — not just theory. ✅ Covers real-world concepts • useState (async updates & batching) • useEffect (execution order & dependencies) • Closures & stale state • Memoization (useMemo, useCallback, React.memo) • Keys & reconciliation • Rendering behavior & performance 💡 Each question includes: ✔ Clean, readable code ✔ Exact output ✔ Clear explanation (why it works that way) This is the kind of practice that helps you think like React, not just memorize it. 📌 Perfect for: • Frontend developers preparing for product-based companies • Developers stuck at “I know React but can’t crack interviews” stage If you want the PDF 👉 Comment “React” and I’ll share it with you. #ReactJS #FrontendDevelopment #JavaScript #WebDevelopment #InterviewPreparation #CodingInterview #ReactDeveloper #LearnToCode

😍A Collection of 100+ Next.js Interview Questions With Answers😍 ✅ 100+ real-world Next.js interview questions with crystal-clear explanations ✅ No fluff. No jargon. Just straight-to-the-point answers you can easily remember ✅ Covers concepts developers often get stuck on during interviews ✅ Perfect for beginners and experienced devs who want to brush up on their skills 𝗙𝗼𝗿 𝗺𝗼𝗿𝗲 𝘀𝘂𝗰𝗵 𝘂𝘀𝗲𝗳𝘂𝗹 𝗰𝗼𝗻𝘁𝗲𝗻𝘁, 𝗱𝗼𝗻'𝘁 𝗳𝗼𝗿𝗴𝗲𝘁 𝘁𝗼 𝗳𝗼𝗹𝗹𝗼𝘄 Muhammad Nouman. #javascript #reactjs #nextjs #webdevelopment

Tricky React Interview Question 🤔 Most developers get confused here… Question: What will happen if you update state directly in React? Example: const [count, setCount] = useState(0); count = count + 1; ❌ setCount(count + 1); ✅ Why is the first one wrong? Because React does NOT detect direct state changes. React only re-renders when you use the state setter function. Wrong way ❌ count = count + 1 Correct way ✅ setCount(count + 1) Reason: React tracks state updates using the setter function. If you change value directly, UI will not update correctly. This is one of the most common mistakes in React interviews. Tip: Always use setter function returned by useState. More React interview questions coming… 🚀 #ReactJS #FrontendDeveloper #JavaScript #WebDevelopment #CodingInterview #ReactInterview #NextJS #SoftwareDeveloper #UIDeveloper

🚀 Just created my own handwritten Frontend Interview Notes! I’ve been revising core JavaScript concepts and decided to put everything together in a simple handwritten style to make learning more clear and visual. This includes: ✔️ Primitive vs Non-Primitive data types ✔️ Functions & Scope (global, block, lexical) ✔️ Callback functions ✔️ Important array methods (map, filter, reduce, every) ✔️ call(), apply(), bind() ✔️ Anonymous functions & NaN The goal was to keep things easy to understand, quick to revise, and more practical for interviews. Sometimes, writing concepts in your own way makes a big difference in understanding them deeply. If you're preparing for frontend interviews, this might help you revise faster! #JavaScript #FrontendDevelopment #WebDevelopment #InterviewPreparation #CodingJourney #Learning

🚨 Most Developers Get This Wrong in React Interviews 👉 Why does a component re-render even when nothing changed? If you can’t confidently answer this… You’re not ready for product-based interviews yet. 💡 React is not just about writing components. It’s about understanding: ⚡ How rendering works ⚡ Why performance issues happen ⚡ How to control re-renders 🔥 Real interview scenarios companies ask: • Why does a child re-render when parent updates? • Why do inline functions cause re-renders? • When does React.memo fail? • useMemo vs useCallback — real difference? • Why does useEffect run twice in React 18? ❌ Most people memorize hooks ✅ Top candidates understand behavior 📄 So I created: 👉 React Re-render & Performance – 30 Scenario-Based Questions This is NOT theory. These are the actual patterns interviewers test. 💬 Comment REACT and I’ll share the PDF #reactjs #frontenddeveloper #javascript #codinginterview #webdevelopment #softwareengineer #reactperformance #learnincode #techcareer #developers #react18 #programming 🚀

🚀 React Interview Series | Day 7: Functional vs Class Components If you're starting with React or preparing for interviews, you’ve probably seen both: 👉 Functional Components 👉 Class Components But what’s the real difference? And which one should you use? 💡 1. Functional Components (Modern Way) These are just simple JavaScript functions. function Greeting() { return <h1>Hello, World!</h1>; } ✅ Easy to read ✅ Less boilerplate ✅ Uses Hooks (useState, useEffect) ✅ Preferred in modern React 💡 2. Class Components (Old Way) These use ES6 classes and have more structure. class Greeting extends React.Component { render() { return <h1>Hello, World!</h1>; } } ⚠️ More complex syntax ⚠️ Uses this keyword ⚠️ Lifecycle methods (componentDidMount, etc.) 🔥 Key Difference (Interview Point) 👉 Functional = Simpler + Hooks 👉 Class = Complex + Lifecycle methods 🎯 Real Talk Today, most companies prefer Functional Components. Class components are mostly found in legacy codebases. 💬 Interview Tip If asked: “Which one should we use?” 👉 Answer: "Functional Components, because they are simpler, cleaner, and support Hooks for state & lifecycle management." https://lnkd.in/gR_ZTUTc 📌 Quick Summary ✔ Functional = Modern + Easy ✔ Class = Legacy + Complex 👨💻 Day 7 Done! Follow for more React Interview Questions 🚀 #React #JavaScript #FrontendDevelopment #WebDevelopment #ReactJS #CodingInterview #LearnToCode #Developers #Programming #100DaysOfCode

❌ 80% of frontend developers can’t clearly explain this in interviews. “Short polling vs Long polling vs Server-side events — what’s the difference?” At first, I explained it in a very textbook way… and honestly, it didn’t land well. Later, I simplified it like this: Short polling is like repeatedly checking your phone for a message every few seconds. Even if there’s nothing new… you still keep checking. Long polling is a bit smarter. You ask once and wait… the server replies only when there’s something new. But after that, you have to ask again. Server-Sent Events feel more natural. You just open the connection once… and the server keeps sending updates whenever they happen. That’s it. No overcomplicated definitions. Just real understanding. And in interviews, this clarity matters more than fancy words. Don't forget to follow Hrithik Garg 🚀 for more. #frontend #javascript #interviews #webdevelopment #systemdesign