Top 100 React JS Interview Questions and Answers - HINDI

Top 100 React Interview Q & A - ENGLISH

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[youcan]

00:02 Prepare and revise to crack React JS interviews
02:34 Understanding the flow of request in React and the role of React in software development.
07:59 Understanding DOM and its role in web development
10:42 Understanding the difference between DOM and Virtual DOM is crucial in React JS.
16:12 Understanding React components and structure
18:36 Difference between single page and multi page applications
23:10 Understanding React Elements and React Babel Library
25:30 Understanding the difference between declarative and imperative syntax in JavaScript
29:51 Setting up a React project involves installing necessary tools and editors.
31:50 Setting up a React project with default folders and files
36:39 Understanding the flow of React components loading and display
39:17 React is a JavaScript library while Angular is a complete framework.
43:40 Understanding TypeScript OOPs concepts and server-side implications
45:58 React is a library for building user interfaces.
50:13 Introduction to state management in React JS
52:34 Props are a way to pass data from parent to child component.
57:25 The public folder contains static assets served directly to the user browser.
59:56 Role of index.js file in React JS applications
1:04:56 Understanding the role of function and return in app.js file
1:07:16 Introduction to arrow functions and return statement in React JS
1:11:43 Importance of organizing code and naming conventions in React applications
1:13:58 React Babel library converts JavaScript code for browser compatibility
1:18:21 Advantages of React JS
1:20:43 Fragment tags in React help to group child elements without adding extra nodes.
1:25:03 Learn about if-else, ternary operators, and conditional rendering in React JS
1:27:26 Explanation of conditional rendering techniques in JavaScript
1:32:19 Understanding Transpiler vs Compiler in JavaScript
1:34:35 Understanding React components and their types
1:39:15 Using props for data passing between React components
1:41:41 Ways to avoid prop drilling in React JS
1:46:24 Importance of class components and data passing in React JS
1:48:49 Understanding the role of 'this' keyword in React JS
1:53:40 Routing and React Router in React JS
1:56:07 Setting up routing in React JS
2:00:56 Understanding the role of the Switch Component in React Router
2:03:28 React Hooks are inbuilt functions for managing state and life cycle features in functional components.
2:08:22 State management is necessary for updating UI and managing stateful data.
2:10:44 Role of useState hook in managing state
2:15:48 Explanation of useState hook
2:18:03 Understanding the use of the useEffect hook in React JS
2:22:35 Understanding the use of the dependency array in React hooks
2:24:58 Understanding dependency array in React JS
2:29:33 Using context in React for data sharing
2:31:54 Using React Context to avoid prop drilling
2:36:44 Implementing dark theme across website components
2:39:03 Understanding React component life cycle phases
2:43:33 Understanding component life cycle methods
2:45:56 Super keyword in React JS constructor
2:50:33 Introduction to state management in React JS using class components and hooks
2:52:56 Explanation of ComponentDidMount lifecycle method in React component
2:57:46 Understanding state management in React components
3:00:12 Discussing controlled and uncontrolled components in React JS
3:04:53 Control components ensure a single source of truth
3:07:27 Benefits of using Uncontrolled Components for form handling
3:12:17 Code splitting in React JS
3:15:01 Implementing code splitting with React Suspense and Lazy
3:19:31 Component used for fallback UI while lazy loading parent component
3:21:51 Benefits and challenges of small data in React JS
3:26:31 Understanding Higher Order Components in React
3:28:51 Understanding higher order components in React
3:33:54 React and React Native application deployment
3:36:38 React Context API simplifies state management and eliminates prop drilling
3:41:08 React Profiler allows developers to analyze React application performance
3:43:24 Understanding React JS profilers and API calls
3:47:55 Optimizing React application performance
3:50:27 Reactive programming focuses on reacting to changes and events in a declarative and non-imperative programming style.
3:55:32 Explaining the process of passing values between parent and child components in React JS
3:57:52 Encouragement for completing questions and answers

[shubhamWF]

Q1. What is React? What is the Role of React in software development? Q2. What are the Key Features of React?
Q3. What is DOM? What is the difference between HTML and DOM? Q4. What is Virtual DOM? Difference between DOM and Virtual DOM? Q5. What are React Components? What are the main elements of it? Q6. What is SPA(Single Page Application)?
Q7. What are the 5 Advantages of React?
Q8. What are the Disadvantages of React?
Q9. What is the role of JSX in React? (3 points)
Q10. What is the difference between Declarative & Imperative syntax?


Q1. What is Arrow Function Expression in JSX? V. IMP.
Q2. How to Setup React first project?
Q3. What are the Main Files in a React project?
Q4. How React App Load and display the components in browser? V. IMP.
Q5. What is the difference between React and Angular?
Q6. What are other 5 JS frameworks other than React?
Q7. Whether React is a Framework or a Library? What is the difference?
Q8. How React provides Reusability and Composition?
Q9. What are State, Stateless, Stateful and State Management terms? Q10. What are Props n JSX? V. IMP.


Q1. What is NPM? What is the role of node_modules folder? V. IMP.
Q2. What is the role of public folder in React?
Q3. What is the role of src folder in React?
Q4. What is the role of index.html page in React?
V. IMP.
Q5. What is the role of index.js file and ReactDOM in React? V. IMP. Q6. What is the role of App.js file in React?
V. IMP.
Q7. What is the role of function and return inside App.js?
Q8. Can we have a function without a return inside App.js?
Q9. What is the role of export default inside App.js?
Q10. Does the file name and the component name must be same in React




Q1. What is the role of JSX in React? (3 points)
Q2. What are the 5 Advantages of JSX?
Q3. What is Babel?
Q4. What is the role of Fragment in JSX?
Q5. What is Spread Operator in JSX?
Q6. What are the types of Conditional Rendering in JSX? V. IMP.
Q7. How do you iterate over a list in JSX? What is map() method?
Q8. Can a browser read a JSX File?
Q9. What is Transpiler? What is the difference between Compiler & Transpile
Q10. Is it possible to use JSX without React?


Q1. What are React Components? What are the main elements of it?
V. IMP.
Q2. What are the Types of React components? What are Functional Components? V. IMP. Q3. How do you pass data between functional components in React?
Q4. What is Prop Drilling in React?
V. IMP.
Q5. Why to Avoid Prop Drilling? In how many ways can avoid Prop Drilling?
V. IMP.
V. IMP.
Q6. What are Class Components In React?
Q7. How to pass data between class components in React?
Q8. What is the role of this keyword in class components?
Q9. What are the 5 differences btw Functional components & Class components? V. IMP.


Q1. What is Routing and Router in React?
Q2. How to Implement Routing in React?
Q3. What are the roles of <Routes> & <Route> component in React Routing?
Q4. What are Route Parameters in React Routing?
Q5. What is the role of Switch Component in React Routing?
Q6. What is the role of exact prop in React Routing?



Q1. What are React Hooks? What are the Top React Hooks?
Q2. What are State, Stateless, Stateful and State Management terms? Q3. What is the role of useState() hook and how it works?
Q4. What is the role of use Effect(). How it works and what is its use?
Q5. What is Dependency Array in useEffect() hook?
Q6. What is the meaning of the empty array [] in the useEffect()?




Q1. What is the role of useContext() hook?
Q2. What is createContext() method? What are Provider & Consumer properties? Q3. When to use useContext() hook instead of props in real applications?
Q4. What are the similarities between useState() and useReducer() hook?
V. IMP.
Q5. What is useReducer() hook? When to use useState() and when useReducer()? V. IMP.
Q6. What are the differences between useState() and useReducer() Hook?
Q7. What are dispatch & reducer function in useReducer Hook?
Q8. What is the purpose of passing initial state as an object in UseReducer?



Q1. What are Component life cycle phases?
Q2. What are Component life cycle methods?
Q3. What are Constructors in class components? When to use them?
Q4. What is the role of super keyword in constructor?
Q5. What is the role of render() method in component life cycle?
Q6. How the State can be maintained in a class component?
Q7. What is the role of componentDidMount() method in component life cycle?




Q1. What are Controlled Components in React?
V. IMP.
Q2. What are the Differences btw Controlled & Uncontrolled Components? V. IMP. Q3. What are characteristics of controlled components?
Q4. What are the advantages of using controlled components in React forms?
Q5. How to handle forms in React?
Q6. How can you handle multiple input fields in a controlled form?
Q7. How do you handle form validation in a controlled component?
Q8. In what scenarios might using uncontrolled components be advantageous?



Q1. What is Code Splitting in React?
Q2. How to Implement Code Splitting in React?
Q3. What is the role of Lazy and Suspense methods in React? V. IMP.
Q4. What are the Pros and Cons of Code Splitting?
Q5. What is the role of the import() function in code splitting?
Q6. What is the purpose of the fallback prop in Suspense?
Q7. Can you dynamically load CSS files using code splitting in React?
Q8. How do you inspect and analyze the generated chunks in a React application?

[ahmedaftab]

Hi, I am from Pakistan, I just passed my interview for a remote job in a fintech company and this video helped me a lot in React.js and JavaScript question (I also watched your JavaScript interview questions videos), thank you Sir

[er.nitingarg]

Q1. What is React? What is the Role of React in software development? Q2. What are the Key Features of React?
Q3. What is DOM? What is the difference between HTML and DOM? Q4. What is Virtual DOM? Difference between DOM and Virtual DOM? Q5. What are React Components? What are the main elements of it? Q6. What is SPA(Single Page Application)?
Q7. What are the 5 Advantages of React?
Q8. What are the Disadvantages of React?
Q9. What is the role of JSX in React? (3 points)
Q10. What is the difference between Declarative & Imperative syntax?


Q1. 28:05 What is Arrow Function Expression in JSX? V. IMP.
Q2. 30:28 How to Setup React first project?
Q3. 33:45 What are the Main Files in a React project?
Q4. 36:45 How React App Load and display the components in browser? V. IMP.
Q5. 39:38 What is the difference between React and Angular?
Q6. 44:35 What are other 5 JS frameworks other than React?
Q7. Whether React is a Framework or a Library? What is the difference?
Q8. How React provides Reusability and Composition?
Q9. What are State, Stateless, Stateful and State Management terms? Q10. What are Props n JSX? V. IMP.


Q1. What is NPM? What is the role of node_modules folder? V. IMP.
Q2. What is the role of public folder in React?
Q3. What is the role of src folder in React?
Q4. What is the role of index.html page in React?
V. IMP.
Q5. What is the role of index.js file and ReactDOM in React? V. IMP. Q6. What is the role of App.js file in React?
V. IMP.
Q7. What is the role of function and return inside App.js?
Q8. Can we have a function without a return inside App.js?
Q9. What is the role of export default inside App.js?
Q10. Does the file name and the component name must be same in React




Q1. What is the role of JSX in React? (3 points)
Q2. What are the 5 Advantages of JSX?
Q3. What is Babel?
Q4. What is the role of Fragment in JSX?
Q5. What is Spread Operator in JSX?
Q6. What are the types of Conditional Rendering in JSX? V. IMP.
Q7. How do you iterate over a list in JSX? What is map() method?
Q8. Can a browser read a JSX File?
Q9. What is Transpiler? What is the difference between Compiler & Transpile
Q10. Is it possible to use JSX without React?


Q1. What are React Components? What are the main elements of it?
V. IMP.
Q2. What are the Types of React components? What are Functional Components? V. IMP. Q3. How do you pass data between functional components in React?
Q4. What is Prop Drilling in React?
V. IMP.
Q5. Why to Avoid Prop Drilling? In how many ways can avoid Prop Drilling?
V. IMP.
V. IMP.
Q6. What are Class Components In React?
Q7. How to pass data between class components in React?
Q8. What is the role of this keyword in class components?
Q9. What are the 5 differences btw Functional components & Class components? V. IMP.


Q1. What is Routing and Router in React?
Q2. How to Implement Routing in React?
Q3. What are the roles of <Routes> & <Route> component in React Routing?
Q4. What are Route Parameters in React Routing?
Q5. What is the role of Switch Component in React Routing?
Q6. What is the role of exact prop in React Routing?



Q1. What are React Hooks? What are the Top React Hooks?
Q2. What are State, Stateless, Stateful and State Management terms? Q3. What is the role of useState() hook and how it works?
Q4. What is the role of use Effect(). How it works and what is its use?
Q5. What is Dependency Array in useEffect() hook?
Q6. What is the meaning of the empty array [] in the useEffect()?




Q1. What is the role of useContext() hook?
Q2. What is createContext() method? What are Provider & Consumer properties? Q3. When to use useContext() hook instead of props in real applications?
Q4. What are the similarities between useState() and useReducer() hook?
V. IMP.
Q5. What is useReducer() hook? When to use useState() and when useReducer()? V. IMP.
Q6. What are the differences between useState() and useReducer() Hook?
Q7. What are dispatch & reducer function in useReducer Hook?
Q8. What is the purpose of passing initial state as an object in UseReducer?



Q1. What are Component life cycle phases?
Q2. What are Component life cycle methods?
Q3. What are Constructors in class components? When to use them?
Q4. What is the role of super keyword in constructor?
Q5. What is the role of render() method in component life cycle?
Q6. How the State can be maintained in a class component?
Q7. What is the role of componentDidMount() method in component life cycle?




Q1. What are Controlled Components in React?
V. IMP.
Q2. What are the Differences btw Controlled & Uncontrolled Components? V. IMP. Q3. What are characteristics of controlled components?
Q4. What are the advantages of using controlled components in React forms?
Q5. How to handle forms in React?
Q6. How can you handle multiple input fields in a controlled form?
Q7. How do you handle form validation in a controlled component?
Q8. In what scenarios might using uncontrolled components be advantageous?



Q1. What is Code Splitting in React?
Q2. How to Implement Code Splitting in React?
Q3. What is the role of Lazy and Suspense methods in React? V. IMP.
Q4. What are the Pros and Cons of Code Splitting?
Q5. What is the role of the import() function in code splitting?
Q6. What is the purpose of the fallback prop in Suspense?
Q7. Can you dynamically load CSS files using code splitting in React?
Q8. How do you inspect and analyze the generated chunks in a React application?

[poojasingh-ylch]

The best interview preparation channel, material, explanation and offcourse you sir.

[matheguruworld]

Chapter 1 Basics-I 2:42
Chapter 2 Basics-II 27:15
Chapter 3 React Project - Files & Folders 54:08
Chapter 4 JSX 1:12:16
Chapter 5 Components-Functional/Class 1:34:55
Chapter 6 Routing 1:53:23
Chapter 7 Hooks-usestate/useEffect 2:04:30
Chapter 8 Hook useContext/useReducer 2:28:20
Chapter 11 Components lifecycle Methods -I 2:38:05
Chapter 13 Controlled & Uncontrolled Components 2:57:09
Chapter 14 Code Splitting 3:10:16
Chapter 15 React & Others 3:27:00

[madhavigaikwad]

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[AmitKumarGupta-zf]

Thank you sir, I got selected in TCS(Digita) and your important javascript and this React interview question tutorial helps me lot to cracked my interview 🙏🙏 ...

[piyushkumar]

at 24:29 Babel is not a part of React or ReactDOm library its part of bundler library named parcel. Once we actually do npm i parcel bable comes along with that.
31:00 npx create-react-app is dead now in 2025

[devrajsongara]

Now. I'm confident for my next frontend interview because last time I failed due to less knowledge of React.

[AnitaBehera-tt]

Hi Sir.. I want to share my success story with you. Just because of your guidance in YouTube video, I got job in top MNC company for ReactJs and I am writing this comment after my probation period finished. Thankyou so much sir ..

[ANANDKUMAR-inpc]

With the help of your video and your YouTube channel, I cracked the interview.

[sachintiwari]

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[PoojithaSrinivasan]

This is the best interview preparation video. The way you have explained every topic very easily is really helpful in preparation

[AmitSingh-tfyu]

hello Sir I follow this full video, and after that I given a React based interview, in there i answered 4 correct questions out 5, so it it really helpfull, sir plz make video for logical questions for javascript, react, and angular

[sarcasmpro]

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[nihitjain]

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Reminder -sirf videos se kuch nhi hoga, apni journey ko aur better karna ka leyaa bohut important hai videos, must watch while preparing for interviews

[wasiquekhan]

Salam sir
Today i got job in react after preparation your giving question answer with 30k salary
Thanks sir you are great
Love from mumbai

[parampatel]

Best video in internet for react interview 😊

[simple_user]

Great work sir! Can you please make a similar video for React Native Interview Questions? I couldn't find a proper video for react native on youtube.There might be many students like me facing the similar issue. Please help us out!!!🥺