React Interview Questions & Answers

⚛️ React Interview Questions & Answers 💻🔥

Preparing for a React interview? Here are some must-know questions with simple answers 👇

🔹 What is React?

A JavaScript library used to build fast and interactive user interfaces.

🔹 What are components?

Reusable building blocks of a React app (Functional & Class components).

🔹 What is JSX?

A syntax that lets you write HTML inside JavaScript.

🔹 What is Virtual DOM?

A lightweight copy of the real DOM that improves performance by updating only changed elements.

🔹 What are props?

Read-only inputs passed from parent to child components.

🔹 What is state?

A built-in object used to manage dynamic data in a component.

🔹 Difference between props and state?

Props are immutable (read-only), state is mutable (can change).

🔹 What are React Hooks?

Functions like `useState` and `useEffect` that let you use state and lifecycle features in functional components.

🔹 What is useEffect?

A hook used for side effects like API calls and subscriptions.

🔹 What is a key in React?

A unique identifier used in lists to help React efficiently update elements.

🔹 What is React Router?

A library for navigation in single-page applications.

💡 Pro Tip:

Don’t just memorize — build projects and understand concepts deeply!

🚀 Crack your React interview with confidence

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