Hrithik Garg 🚀’s Post

🚀 React Interview Question : What is the useReducer hook and when should you use it? 💡 useReducer is a React hook that lets you manage state using a centralized function (reducer) that handles all state updates based on actions. 🔹 Basic Syntax const [state, dispatch] = useReducer(reducer, initialState); state → current state dispatch → function to send actions reducer → function that decides how state changes 🔹 How it works const reducer = (state, action) => { switch (action.type) { case "INCREMENT": return { count: state.count + 1 }; case "DECREMENT": return { count: state.count - 1 }; default: return state; } }; dispatch({ type: "INCREMENT" }); 🔹 Why use useReducer? - helps manage complex state logic - keeps state updates organized and predictable - avoids messy multiple useState calls 🔹 When should you use it? - state has multiple related values - logic involves multiple conditions (switch/if) - state updates depend on previous state - for better structure & scalability 🔹 Example Use Cases - form handling with many fields - complex UI state (toggles, filters, steps) - managing state transitions (like loading → success → error) Follow Tarun Kumar for tech content, coding tips, and interview prep #ReactJS #JavaScript #WebDevelopment #FrontendDeveloper #Coding #Programming #Developers #SoftwareEngineer #Tech

React Interview Guide: Components — From Basic to Advanced to Expert I created a detailed interview PDF guide covering one of the most important foundations of React: Components. This guide covers: ✅ Functional vs Class Components ✅ Props and PropTypes ✅ Component Composition ✅ Children Prop in React ✅ Basic to Advanced to Expert-level concepts ✅ Interview questions with answers ✅ Coding examples and practical scenarios React is component-driven, and understanding components deeply can make a big difference in interviews, real-world projects, and frontend architecture. Whether you are preparing for interviews, improving your React fundamentals, or revising before switching jobs, this guide can help you build clarity step by step. 📌 Topic: React Components 📄 Format: Interview PDF Guide 🎯 Level: Beginner → Advanced → Expert Happy learning and keep building! 🚀 #ReactJS #React #JavaScript #FrontendDevelopment #WebDevelopment #FrontendDeveloper #SoftwareEngineer #InterviewPreparation #CodingInterview #ReactDeveloper #JavaScriptDeveloper #TechInterview #Programming #LearnReact #DeveloperCommunity #100DaysOfCode #WebDev #CareerGrowth #SoftwareDevelopment #Components #Props #ReactInterview

🚀 Built something for every frontend developer preparing for interviews! I’ve created a complete Preparation Guide that covers everything you actually need 👇 💡 What you’ll find inside: • 🌐 HTML, CSS & JavaScript fundamentals • ⚛️ Core concepts of React • 🧠 Machine Coding Round Questions • 📚 Structured topics & subtopics for focused learning No more random resources — everything is organized in one place to help you prepare smarter, not harder 🎯 🔗 Check it out: https://lnkd.in/geXQnzhA Would love your feedback 🙌 Let’s help each other grow 🚀 #FrontendDeveloper #React #JavaScript #WebDevelopment #CodingInterview #MachineCoding #HTML #CSS

Just wrapped up a 2-hour interview marathon for a Senior Frontend role, and honestly? It was a reality check on why "knowing React" is never just about React. The process was heavily focused on machine coding and core JavaScript internals. Here’s a quick breakdown for anyone currently in the interview loop: The Rounds Machine Coding (90 mins): I was tasked with building a Star Rating Component from scratch. It sounds simple, but the focus was on reusability, handling half-stars, and ensuring keyboard accessibility. JS Deep Dive: We spent a lot of time on the Event Loop and Promises. I had to predict the output of a nested setTimeout and async/await block—it’s easy to trip up when you're under pressure. React Patterns: Discussing when to use useMemo versus useCallback and the cost of premature optimization. What they were actually looking for: It wasn’t just about making the code work. The interviewer pushed on Edge cases: What happens if the API fails during a debounced search? Code Quality: Clean naming conventions and folder structure. Optimization: Reducing unnecessary re-renders in the UI. A Realistic Mistake: I initially struggled with a closure-based question involving a useEffect cleanup. I had to take a step back, talk through my confusion, and refactor. It’s okay not to be perfect—they wanted to see how I debug when I'm stuck. Key Takeaway: Don't ignore the fundamentals. Frameworks change, but the Event Loop is forever. If you’re prepping for frontend roles and want to chat about these specific rounds, feel free to reach out. Happy to share what worked for me! #FrontendDevelopment #Javascript #ReactJS #InterviewPrep

🚨 Still preparing for React interviews the hard way? Most developers: ❌ Watch random tutorials ❌ Google the same questions again & again ❌ Forget concepts during interviews And that’s exactly why they get rejected. So I fixed this 👇 I created a complete React Interview Questions & Answers PDF with 100+ real questions that actually get asked in interviews � React Interview Questions Answers📝 .pdf 💡 What’s inside? ✔ React fundamentals (JSX, Props, State) ✔ Hooks (useState, useEffect, useReducer, etc.) ✔ Virtual DOM & performance concepts ✔ Redux & state management ✔ Advanced topics (memo, refs, SSR, optimization) ✔ Real interview-level questions with answers 🎯 If you're a: → Beginner struggling with concepts → Developer preparing for interviews → MERN dev aiming for better opportunities This will save you hours of searching. 📌 Don’t just scroll… 👉 Save this post (you’ll need it later) 🔁 Repost to help other developers 💬 Comment “REACT” and I’ll share more resources 🔥 Follow me for: Daily dev content Real interview prep MERN roadmap & resources #reactjs #webdevelopment #frontenddeveloper #mernstack #javascript #coding #developers #programming #techcareer #interviewprep #softwaredeveloper #100DaysOfCode

React Components Interview Q&A Guide — Basic to Expert Level I created a complete React Components Interview Guide in Q&A format, covering concepts from beginner to expert level. This guide includes: ✅ Functional Components ✅ Props and Children ✅ Component Composition ✅ State and Re-rendering ✅ Controlled vs Uncontrolled Components ✅ Memoization and Performance ✅ Refs and Forwarding Refs ✅ Error Boundaries ✅ Suspense and Lazy Loading ✅ Server vs Client Components ✅ Common Edge Cases ✅ Interview-style Questions & Answers React components look simple at first, but many interview questions test deeper understanding: “How does React preserve state?” “When does a component re-render?” “Why should keys be stable?” “What is the real use of children?” “When should we avoid memo?” This guide is useful for: 🔹 Frontend Developers 🔹 React Learners 🔹 Interview Preparation 🔹 JavaScript Developers moving into React 🔹 Developers revising component-level architecture React is not just about writing JSX. Understanding components properly helps you write cleaner, reusable, scalable, and interview-ready frontend code. If you are preparing for React interviews, this can be a strong revision resource. #ReactJS #React #JavaScript #FrontendDevelopment #WebDevelopment #InterviewPreparation #ReactInterview #FrontendInterview #SoftwareDeveloper #SoftwareEngineering #JavaScriptDeveloper #CodingInterview #Programming #TechCareers #100DaysOfCode #DeveloperCommunity #WebDeveloper #UIEngineering #FrontendEngineer #LearnReact

𝗠𝗼𝘀𝘁 𝗽𝗲𝗼𝗽𝗹𝗲 𝗹𝗲𝗮𝗿𝗻 𝗥𝗲𝗮𝗰𝘁. 𝗩𝗲𝗿𝘆 𝗳𝗲𝘄 𝗰𝗮𝗻 𝗲𝘅𝗽𝗹𝗮𝗶𝗻 𝗶𝘁 𝗶𝗻 𝗮𝗻 𝗶𝗻𝘁𝗲𝗿𝘃𝗶𝗲𝘄. That’s the difference between building projects… and clearing interviews. You don’t need more tutorials. 𝗬𝗼𝘂 𝗻𝗲𝗲𝗱 𝗰𝗹𝗮𝗿𝗶𝘁𝘆 𝗼𝗻 𝗰𝗼𝗻𝗰𝗲𝗽𝘁𝘀. 𝗠𝗼𝘀𝘁 𝗰𝗮𝗻𝗱𝗶𝗱𝗮𝘁𝗲𝘀: Learn basics Build small apps Struggle to explain “why” 𝗧𝗵𝗮𝘁’𝘀 𝘄𝗵𝘆 𝘁𝗵𝗲𝘆 𝗴𝗲𝘁 𝗿𝗲𝗷𝗲𝗰𝘁𝗲𝗱. Because interviews don’t test coding. 𝗧𝗵𝗲𝘆 𝘁𝗲𝘀𝘁 𝘂𝗻𝗱𝗲𝗿𝘀𝘁𝗮𝗻𝗱𝗶𝗻𝗴. 𝗛𝗲𝗿𝗲’𝘀 𝘄𝗵𝗮𝘁 𝗮𝗰𝘁𝘂𝗮𝗹𝗹𝘆 𝗺𝗮𝘁𝘁𝗲𝗿𝘀: React fundamentals JSX & rendering Components & lifecycle Props & state Hooks (useState, useEffect, useMemo, useCallback) Context API Event handling Lists & conditional rendering API integration Routing Performance optimization Clean architecture 𝗥𝗲𝗮𝗹 𝗴𝗮𝗺𝗲: Coding → Easy 𝗘𝘅𝗽𝗹𝗮𝗶𝗻𝗶𝗻𝗴 → 𝗦𝗸𝗶𝗹𝗹 𝗞𝗲𝘆 𝗶𝗻𝘀𝗶𝗴𝗵𝘁: You don’t need to know everything. 𝗬𝗼𝘂 𝗻𝗲𝗲𝗱 𝘁𝗼 𝗸𝗻𝗼𝘄 𝗰𝗼𝗿𝗲 𝗰𝗼𝗻𝗰𝗲𝗽𝘁𝘀 𝗱𝗲𝗲𝗽𝗹𝘆. Build. Break. Explain. Repeat. 𝗖𝗼𝗻𝗻𝗲𝗰𝘁 𝘄𝗶𝘁𝗵 𝗺𝗲 𝗖𝗼𝗺𝗺𝗲𝗻𝘁 𝗶𝗳 𝘆𝗼𝘂 𝘄𝗮𝗻𝘁 𝗳𝘂𝗹𝗹 𝗶𝗻𝘁𝗲𝗿𝘃𝗶𝗲𝘄 𝗻𝗼𝘁𝗲𝘀 Credits - Respective Owner #ReactJS #FrontendDevelopment #WebDevelopment #JavaScript #CodingInterview

Frontend interviews aren't just about centering a div anymore. They've gotten way more intense, but these are the resources that actually helped things click for me. 📺 JSer for deep JS internals: youtube.com/@jserjser 💻 BigFrontend for tricky challenges (found via JSer!): bigfrontend.dev 🏗️ Frontend Masters for System Design and Interview prep https://lnkd.in/dzHMsF35 https://lnkd.in/d-6nN5Xf What are you all using to stay sharp lately? Would love to hear your favorites.

🚀 ReactJS Interview Breakdown — Topic-Wise Questions You MUST Prepare 👇 Just completed a strong technical round, and here’s a structured breakdown of questions asked topic-wise 👇 --- 🧠 JavaScript (Core Concepts) - What is the Event Loop? How does async execution work? - Output-based questions: - "10 > 9 > 8" → why? - Array ".push()" return value behavior - Type coercion and comparison logic --- ⚛️ ReactJS - How does rendering work in React? - What is the role of "useEffect"? (dependency array, cleanup) - Difference between "useMemo" and "useCallback" - When do unnecessary re-renders happen? --- 🧭 React Router - Difference between "useNavigate" and "useLocation" - When to use each in real scenarios --- 🔄 State Management (Redux) - Redux vs Redux Toolkit - What is Store vs State? - What does store actually contain? --- 🌐 API Handling - What are Axios Interceptors? - Where have you used them in real projects? - Handling auth tokens & global error handling --- 💻 Coding Questions - Find starting index of substring (case-sensitive & insensitive) - Find ALL occurrences of a word - Handle edge cases (ignore punctuation like ".", "!") - Group array of objects → "{ age: [names] }" - Write polyfill for "Array.prototype.filter" - Merge two arrays and sort (without inbuilt methods) --- 🔥 What they really evaluate - Problem-solving approach - Edge case handling - Clean and optimized code - Real-world experience over theory --- 💡 If you’re preparing for React interviews: 👉 Focus on concept clarity + coding + real use cases --- Drop a 🔥 if you want: - Answers to these questions - Machine coding patterns - Last-minute revision sheet #ReactJS #JavaScript #FrontendInterview #Redux #CodingInterview #WebDevelopment

🚀 Cracked Some Real-World ReactJS Concepts in Interview Today! Had an interesting discussion in my recent ReactJS interview, and honestly — it wasn’t about syntax, it was about how you think as a developer. Here are some key concepts that stood out 👇 🔥 1. Handling Duplicates Across Arrays (Real-world logic) Not just removing duplicates — but eliminating values completely if they appear more than once (even across arrays). 👉 Focus: Problem-solving + data structures (HashMap mindset) --- ⚛️ 2. Reusable Component Design (Button Example) Instead of repeating UI logic everywhere: 👉 Build once → reuse everywhere 👉 Props-driven design (variant, handlers, states) 💡 This shows how well you understand scalable frontend architecture --- 👀 3. "hidden" vs Conditional Rendering This was tricky but important: - "hidden" → element exists in DOM (just not visible) - Conditional rendering → element doesn’t exist at all 👉 Real takeaway: “Visibility ≠ Lifecycle” --- 🔁 4. "useEffect" Pitfalls (Very Important!) One small mistake = multiple API calls / performance issues ❌ Missing dependency array ❌ Unstable dependencies ✅ Always control execution with proper dependencies --- 🧠 Biggest Learning Interviewers are not checking if you know React… They’re checking if you can build scalable, performant applications --- 💬 If you're preparing for React interviews: Don’t just learn concepts — 👉 Think in terms of real-world usage, performance, and edge cases --- #ReactJS #FrontendDeveloper #JavaScript #WebDevelopment #InterviewPreparation #SoftwareEngineer #Learning #TechInterviews