❓ 1. What is React and why is it used?
👉 Answer:
React is a JavaScript library used for building user interfaces, especially single-page applications. It focuses on reusable components, performance optimization, and easier UI updates using concepts like Virtual DOM and declarative rendering.
React is popular because it:
- Improves development speed with reusable components
- Provides efficient UI updates using Virtual DOM
- Supports strong community and ecosystem
📌 React allows developers to build dynamic interfaces by breaking UI into reusable components and updating only changed parts instead of reloading the entire page.
❓ 2. What is JSX in React?
👉 Answer:
JSX stands for JavaScript XML. It allows developers to write HTML-like syntax inside JavaScript code.
Example:
const element =
Hello Developer!
;JSX improves readability and simplifies UI creation. Browsers cannot understand JSX directly, so it gets converted into standard JavaScript before execution.
❓ 3. What is the difference between Props and State?
👉 Answer:
Props State
Passed from parent component Managed inside component
Immutable (read-only) Mutable (changeable)
Used for communication Used for managing data
Props help share data between components, while state controls component behavior and updates UI when changed.
❓ 4. What is Virtual DOM and how does it improve performance?
👉 Answer:
Virtual DOM is a lightweight copy of the real DOM. When changes occur, React updates the Virtual DOM first, compares it with the previous version, and updates only changed elements in the real DOM.
- This improves performance because:
- Reduces unnecessary DOM updates
- Makes UI rendering faster
- Improves overall user experience
React performs this comparison process using a technique called reconciliation.
❓ 5. What are React Hooks?
👉 Answer:
Hooks allow functional components to use state and lifecycle features without class components.
- Popular Hooks include:
- useState → Manage component state
- useEffect → Handle side effects like API calls
- useContext → Share global data
Hooks must follow certain rules, like being called only at the top level of components and only inside React functions.
Mastering React fundamentals like JSX, Hooks, Virtual DOM, and component data flow builds a strong foundation for advanced frontend development. Learning multiple frameworks like React and Angular can also help you become a versatile developer.
👉 Explore more frontend tutorials and guides here:
https://www.quipoin.com/tutorial/angular
Top comments (0)