Top 50 React Interview Questions & Answers

Ace Your Frontend Interview

React interviews can be tough, often focusing on performance optimization and internal architecture rather than just how to use hooks.

1. What is the Virtual DOM?

The Virtual DOM is a lightweight JavaScript representation of the actual DOM. React uses it to calculate the minimum number of changes required to update the real DOM, making the rendering process significantly faster.

2. Difference between Server Components and Client Components?

Server Components render exclusively on the server, reducing bundle size and improving initial page load. Client Components render on the browser and allow for interactivity (like onClick events) and hooks (like useState).

3. How does React handle re-rendering?

React re-renders a component when its state or props change. By using React.memo, useMemo, and useCallback, developers can prevent unnecessary re-renders of child components.

Practice makes perfect

Don't just memorize these answers. Build a small project and try to explain these concepts while walking through your code.