React JS MCQs 4

What is the purpose of the useRef hook in React?

• a) To create references to DOM elements or React components (Correct Answer)
• b) To manage component state
• c) To subscribe to context changes
• d) To perform asynchronous operations

Which of the following statements is true about React portals?

• a) React portals allow you to render components outside the DOM hierarchy of the parent component (Correct Answer)
• b) React portals are used to create reusable UI components
• c) React portals are deprecated in favor of other techniques
• d) React portals are used for server-side rendering only

What is the purpose of the forwardRef function in React?

• a) To forward props from parent to child components
• b) To forward DOM attributes from parent to child components
• c) To forward refs from parent to child components (Correct Answer)
• d) To forward context from parent to child components

Which of the following is NOT a valid lifecycle method in React?

• a) componentWillMount
• b) componentWillUpdate
• c) componentWillReceiveProps
• d) componentWillUnmount (Correct Answer)

What is the purpose of the React.Fragment component in React?

• a) To create a new React component
• b) To group multiple elements without adding extra nodes to the DOM (Correct Answer)
• c) To define global styles for the entire application
• d) To manage component state

Which of the following statements about React context is true?

• a) React context is used to manage component state
• b) React context allows you to pass data through the component tree without having to pass props down manually (Correct Answer)
• c) React context is primarily used for styling components
• d) React context is a replacement for Redux

What is the purpose of the createRef function in React?

• a) To create references to DOM elements or React components
• b) To create new React components
• c) To create new context objects
• d) To create references to functional components (Correct Answer)

Which of the following is NOT a valid way to style components in React?

• a) Inline styles
• b) External CSS files
• c) Styled-components library
• d) Using <style> tags inside JSX (Correct Answer)

What is the purpose of the dangerouslySetInnerHTML attribute in React?

• a) To sanitize HTML input before rendering it
• b) To escape special characters in HTML input
• c) To set the inner HTML of a React component from a string (Correct Answer)
• d) To prevent XSS attacks

What is the purpose of the useEffect hook in React?

• a) To perform side effects in functional components (Correct Answer)
• b) To manage component state
• c) To fetch data from an API
• d) To subscribe to context changes