- **[Beginner ReactJS](#beginner-reactjs) ⚛️**

- **[Intermediate ReactJS](#intermediate-reactjs) ⚛️ 🚀**

- **[Advanced ReactJS](#advanced-reactjs) ⚛️ 🔥**

1. How does React use the virtual DOM to make things faster?

2. What are React Hooks, and why are they useful?

3. Can you explain the difference between controlled and uncontrolled components in React?

4. What is JSX in React, and how is it different from regular HTML? Can you provide an example?

5. How does the `useEffect` hook help in React? Can you give an example?

6. Why is the `key` attribute important when working with lists in React?

7. What is the purpose of the `setState` method in React, and why is it used?

8. Explain the concept of props in React and how they differ from state.

9. How does conditional rendering work in React, and can you provide an example?

10. What is the significance of the `render` method in a React component?

11. How do you handle forms in React, and what is the role of controlled components?

12. What is the purpose of the `React.Fragment` in React?

1. Can you explain Higher Order Components (HOC) in React in simple terms?

2. What is Redux, and how does it work with React?

3. Explain the Flux architecture briefly and its connection to React.

4. When should you use Redux instead of local state management in React?

5. How is React Context different from Redux for state management?

6. What is the `shouldComponentUpdate` method in React, and why is it important for performance?

7. What are useMemo and useCallback hooks in React, and when do you use each?

8. Can you give an example of code splitting in React? Why is it useful?

9. What is server-side rendering (SSR) in React, and why might you use it?

10. How does the `dangerouslySetInnerHTML` attribute work in React?

11. What are portals in React, and when might you use them?

12. How does lazy loading improve React app performance?

13. How do you prevent unnecessary re-renders in React?

14. Explain the difference between state and context in React.

15. How does event handling differ in React compared to traditional HTML?

16. Explain the concept of "lifting state up" in React and when it is beneficial.

17. What is the significance of the `this` keyword in class components in React?

18. How does error handling work in React applications?

19. What are React refs, and how are they used in React components?

20. How does the `componentDidMount` lifecycle method differ from `useEffect` in functional components?

1. How can a child component communicate with a parent in React?

2. How do you pass data from one React component to another?

3. What is the difference between real DOM and virtual DOM in React?

4. How can you make React re-render only a specific component without the entire browser?

5. What distinguishes stateful and stateless components in React?

6. How do you send data from a parent component to a child component in React?

7. Why did React move away from class-based components?

8. What is the `useEffect` hook, and why is it useful in React?

9. Explain lazy routing in React with a simple example.

10. Why use className instead of class in React for styling?

11. What is an error boundary in React, and why is it helpful?

12. How does Axios differ from Fetch in React, and when would you use each?

13. What are the limitations of React.js?

14. Differences between local storage and session storage in React, and how do you use them?

15. Why is React so popular?

16. What is JSX, and how does it make React development easier?

17. How do `useMemo` and `useCallback` differ in React, and when do you use each?

18. Differences between `useState` and `useReducer` in React and their use cases.

19. Explain the purpose of `React.createRef` in React and when it's preferable.

20. What does the `memo` function do in React, and when would you use it?

21. What is the role of the `useLayoutEffect` hook in React, and when is it used?

22. Differences between shallow rendering and full rendering in React testing.

23. What is the role of the `children` prop in React components?

24. How does React handle routing in Single Page Applications (SPAs)?

25. What does the `dangerouslySetInnerHTML` prop do in React?

26. When and why would you use `React.PureComponent` in React?

27. Explain automatic batching in React and how it improves performance.

28. What is an error boundary in React, and why is it helpful?

29. Differences between useState and useReducer in React and their use cases.

30. What is suspense in the server in React, and how does it contribute to improving user experience in asynchronous operations?

31. What is reconciliation in React, and how does it play a crucial role in updating the DOM efficiently?

32. Differences between Higher Order Components and React Hooks.

33. Differences between functional components and class-based components and why functional components are needed.