70 ReactJs #interview questions

- What is React

- What is useMemo

- What are the features of React

- What is JSX

- What is DOM

- What is Virtual Dom

- What is component life cycle of React class component

- What are fragments in react

- What are props in react

- What are synthetic events in react

- What are the difference between Package.json and Package.lock.json

- What are the differences between client side and server side rendering

- What is state in Reactjs

- What are props

- What are the differences between State and Props in react

- What is props drilling

- What are the disadvantages of props drilling and How we can avoid props drilling

- What are Pure components in React

- Whatare Ref’s in React

- What is meant by forward ref

- What are Error boundaries

- What are Higher order components in react

- What are the differences between controlled and uncontrolled components

- What is useCallback

- What are the differences between useMemo and useCallback

- What are keys in React

- What is Lazy loading in React

- What is suspense in React

- What are custom hooks

- What is useReducer hook

- What are Portals in react

- What is context in react

- Practical question: Give an example of context api usage

- What is the purpose of callback function as an argument of setState()

- Practical question: create a custom hook for increment/decrement counter

- Which lifecycle hooks in class component are replaced with useEffect in functional components

- What is Strict mode in react

- What are the different ways to pass data from child component to parent component in react

- Practical question: How to send data from child to parent using callback functions

- Practical question: How to send the data from child component to parent using useRef

- What is React JS

- What are components in React

- Difference between class and functional components

- What are props in React

- What is state in React

- How does state differ from props

- What is the virtual DOM

- How does the virtual DOM work

- What is a React Hook

- What are the commonly used hooks

- Explain the useState hook.

- Explain the useEffect hook.

- What is the purpose of useReducer

- What are higher-order components (HOCs)

- What is the purpose of useContext

- How does the context API work

- Explain React lifecycle methods.

- What is the purpose of componentDidMount

- What is the purpose of componentDidUpdate

- What is the purpose of componentWillUnmount

- What is React Router

- How do you handle routing in React

- What is lazy loading in React

- What is code splitting

- How do you optimize performance in React

- What are React fragments

- How do you handle events in React

- What is controlled vs uncontrolled components