1. What is React.js?

A programming language A server-side framework A front-end JavaScript library A database management system

2. What does JSX stand for in React.js?

JavaScript XML Java Standard Extension JavaScript XHR Java Syntax Extension

3. Which of the following is NOT a React.js lifecycle method?

componentDidMount componentDidUpdate componentWillMount componentWillRender

4. What is the purpose of state in React.js?

To manage the appearance of the user interface To store and manage data that can change over time To define the layout and styling of components To handle user interactions with the application

5. What is the role of props in React.js?

To handle component state changes To pass data from parent components to child components To manage the routing and navigation in an application To define the structure and layout of a component

6. Which of the following is the correct way to render a React component?

ReactDOM.render(</App />, document.getElementById('root')); React.render(App, document.getElementById('root')); ReactDOM.render(App, document.getElementById('root')); React.render(<Aapp />, document.querySelector('root'));

7. What is the purpose of the key prop in React.js?

To specify the component's position in the virtual DOM To handle user interactions with the component To define the unique identifier for a component in an array To specify the CSS class for the component

8. What is the purpose of the shouldComponentUpdate lifecycle method in React.js?

To update the component's state To control when the component should re-render To handle errors during rendering To fetch data from an external API

9. What is the recommended way to manage form inputs in React.js?

By using the controlled component pattern By using regular HTML form elements By using JavaScript event listeners directly By using the useState hook for each input field

10. Which of the following is a React.js routing library?

React Router React Navigation React Route React Navigator