React Frontend Specialist Mock Test

Q: What is this reactjs mock test?

This is a comprehensive reactjs mock test with 30 questions covering Architecture, Hooks, JSX. It simulates real technical interviews with timed conditions and provides detailed explanations.

Q: How long does the test take?

The test has a time limit of 60 minutes. You can pause and resume, but we recommend completing it in one sitting.

Q: Will I get feedback on my answers?

Yes! After each question, you receive immediate feedback with detailed explanations. At the end, you get a comprehensive report showing your strengths and areas for improvement.

Q: Is this test suitable for FAANG interview preparation?

Absolutely! Our questions are curated by FAANG interviewers and cover the exact topics and difficulty levels you'll encounter in top tech company interviews.

Question 1

What is the primary difference between the 'Render Phase' and the 'Commit Phase' in React?

Answer

Render identifies changes (can be paused), Commit applies changes to the DOM (cannot be paused)

Question 2

Which hook is specifically designed to prevent 'tearing' in concurrent rendering when using exter...

Answer

useSyncExternalStore

Question 3

What is the result of using 'className' instead of 'class' in JSX?

Answer

It applies CSS classes to the rendered DOM element

Question 4

How can you optimize a component that re-renders frequently with the same props?

Answer

Wrap it in React.memo()

Question 5

What does the 'key' prop do in a list of elements?

Answer

It helps React identify which items have changed, been added, or removed for efficient DOM updates

Question 6

When using `useEffect`, what happens if you return a function?

Answer

The function acts as a cleanup mechanism (runs before unmount or next effect run)

Question 7

What is the purpose of `useId` in React 18?

Answer

To generate unique, stable IDs for accessibility attributes that match between server and client

Question 8

How do you define a 'Fragment' in React?

Answer

Both B and C

Question 9

Which hook should be used to store a mutable value that doesn't trigger a re-render when changed?

Answer

useRef

Question 10

What is 'Lifting State Up'?

Answer

Moving state to the closest common ancestor to share data between sibling components

React Frontend Specialist Mock Test

Difficulty

Topics Covered

What You'll Get