React Quiz | ReactJs Interview Quiz

Why Take This Quiz?

React knowledge test: This is not another test. It’s an opportunity to get a measure of how good you are with one of the most widely used JavaScript libraries today.

React interview quiz: Going for a job interview? Ace the frequently asked common React JS quiz questions that interviewers always have in ready stock.

React quiz online: Quick, easy, and free at any given time, anywhere.

What to Expect

In this React JS online quiz, you’ll face questions ranging from the fundamentals of React components, hooks, and state management to more challenging topics like performance optimization and best practices.

Here’s what you’ll get:

MCQ-based React quiz test: Engage with multiple-choice questions that cover essential React concepts.

React JS quiz questions: Each question is designed to encourage critical thinking about how React operates behind the scenes.

React MCQ online test: It’s all about selecting the best answer from a list of options, ensuring you’re prepared for real-world problem-solving.

Who Should Take This React Quiz?

Beginners: Curious about how well you know React? This quiz will help you figure out where to improve.

Intermediate developers: Test your skills and find out if you’re truly ready for a React knowledge test.

Job seekers: Ace your next technical interview with confidence after going through our React interview quiz. If you want more react interview questions then visit react interview questions for freshers.

React Quiz:

What is React primarily used for?
- Backend Development
- Frontend Development
- Mobile App Development
- Database Management
What is JSX in React?
- A syntax extension for JavaScript
- A CSS preprocessor
- A database query language
- A tool for server-side rendering
Which method is used to update the state of a React component?
- updateState()
- refreshState()
- setState()
- resetState()
What is the virtual DOM in React?
- A lightweight representation of the real DOM
- A copy of the browser’s DOM
- A feature of JavaScript
- A new HTML element
What is the purpose of React’s useEffect hook?
- To update the component’s state
- To control the virtual DOM
- To create class components
- To handle side effects in a function component
What does React’s “key” prop help with when rendering lists?
- It changes the list order
- It adds animations to list items
- It helps identify which items have changed
- It removes duplicates from the list
What is a controlled component in React?
- A component that controls its own form data via state
- A component with static data
- A component that updates only when props change
- A component that doesn’t use JSX
Which of the following is NOT a React lifecycle method?
- componentDidMount
- componentWillUnmount
- shouldComponentUpdate
- handleEvent
What is React’s context API used for?
- To pass data through the component tree without props
- To manage state globally
- To handle side effects
- To manage component life cycles
What is the purpose of React’s useState hook?
- To handle side effects in components
- To manage state in function components
- To handle events
- To optimize rendering
What is a React fragment?
- A lifecycle method
- A way to handle state management
- A way to return multiple elements without a wrapper tag
- A custom hook in React
Which hook is used to manage side effects in a function component?
- useState
- useEffect
- useMemo
- useReducer
Which of these is NOT a valid React hook?
- useState
- useEffect
- useContext
- useService
What is the difference between props and state in React?
- Props are read-only, while state can change over time
- State is passed between components, while props are internal
- Props are used for styling, state for behavior
- There is no difference
Which of the following is a common way to handle forms in React?
- Inline CSS handling
- Axios for form submissions
- Controlled components using state
- Event listeners
Which of these is a built-in React hook for performance optimization?
- useMemo
- useEffect
- useState
- useReducer
What does the ReactDOM.render method do?
- It binds event listeners to DOM elements
- It renders a React component into the DOM
- It renders HTML templates
- It compiles React components into vanilla JavaScript
What is the purpose of useReducer in React?
- To manage complex state logic in a component
- To update state directly without setState
- To create side effects in components
- To perform API requests
In which React component lifecycle method is it safe to make an API request?
- render
- componentWillMount
- componentDidMount
- shouldComponentUpdate
What does React.memo do?
- It optimizes state updates
- It optimizes component rendering by memoizing props
- It handles side effects in components
- It manages event handlers
What is the correct way to pass data from a parent component to a child component in React?
- Via state
- Via context
- Via ref
- Via props
What is the purpose of useCallback in React?
- To handle side effects
- To memoize functions and avoid unnecessary re-renders
- To update state directly
- To optimize event handling
Which of the following can cause a React component to re-render?
- Changing the state
- Declaring functions inside the component
- Adding event listeners
- Updating CSS styles
What is the purpose of React’s useRef hook?
- To persist values between renders without causing re-renders
- To trigger re-renders
- To access and manipulate context
- To optimize event handling
How can you prevent a component from re-rendering in React?
- By removing its state
- By using React.memo
- By updating props
- By using setState
Which React hook should you use to manage a complex form with multiple fields?
- useEffect
- useReducer
- useMemo
- useRef
Which hook is used to perform cleanup in React?
- useMemo
- useCallback
- useEffect
- useReducer
How can you optimize performance when rendering a list of items in React?
- By using event handlers
- By using the key prop for each item
- By passing all state to each item
- By using the useState hook
What happens if you return null from a React component?
- An error is thrown
- Nothing is rendered on the screen
- The component re-renders
- The component is unmounted
What is the main advantage of server-side rendering in React?
- Faster initial page load and better SEO
- Faster client-side interactions
- Smaller bundle size
- More control over styles