React is a JavaScript library developed by Facebook for building user interfaces using reusable components and a virtual DOM for efficient rendering.

What are React hooks?

Hooks are functions that allow you to use state and lifecycle features in functional components. Common hooks include useState, useEffect, useContext, and useReducer.

What is the virtual DOM?

The virtual DOM is an in-memory representation of the real DOM. React uses it to determine what changes need to be made and updates only those parts in the actual DOM efficiently.

React.js Interview Questions

91. How do controlled inputs impact accessibility?

92. What are semantic HTML best practices in React?

93. How does React integrate with TypeScript?

94. What are common TypeScript patterns in React applications?

95. What are testing strategies for React applications?

96. How do unit tests differ from integration tests in React?

97. What are React Testing Library principles?

98. How does React differ from Angular and Vue architecturally?

99. What are the biggest performance bottlenecks in large React applications?

100. How would you architect a maintainable React application for a growing engineering team?