react js

1. React.js - A JavaScript Library for
Building User Interfaces
Presented by: [Your Name]
Date: [Insert Date]

2. Introduction to React
• React is an open-source JavaScript library used
for building user interfaces, especially single-
page applications. It allows developers to
create large web applications that can update
and render efficiently in response to data
changes.

3. History of React
• - Developed by Jordan Walke, a software
engineer at Facebook
• - First released in 2013
• - Open-sourced at JSConf US in May 2013
• - Gained popularity due to its simplicity and
performance

4. Core Concepts
• - Components: Reusable UI pieces
• - JSX: JavaScript XML to write HTML in JS
• - Virtual DOM: Efficient UI updates
• - State and Props: Data management within
components

5. JSX in Detail
• JSX is a syntax extension for JavaScript that
looks similar to HTML.
• Example:
• const element = <h1>Hello, world!</h1>;
• JSX makes it easier to write and add HTML in
React.

6. Components in React
• - Functional Components: Simple JavaScript
functions
• - Class Components: ES6 classes with lifecycle
methods
• - Components can accept inputs (props) and
return React elements

7. Virtual DOM Explained
• The Virtual DOM is a lightweight JavaScript
representation of the actual DOM.
• - React updates only changed parts, improving
performance
• - Helps in building fast and dynamic web
applications

8. React Hooks
• - Introduced in React 16.8 to use state and
other features without classes
• - Common hooks:
• • useState – Manage state
• • useEffect – Side effects
• • useContext – Context API
• • useRef, useReducer – Advanced state and
refs

9. Routing in React
• - React Router is the standard library for
routing in React
• - Enables navigation among views of various
components
• - Manages browser history, URL paths
• Example:
• <Route path='/about' element={<About />} />

10. React Project Structure
• - node_modules: Project dependencies
• - public: Static files (index.html)
• - src: Main application code
• - App.js: Main component
• - index.js: Entry point for rendering React app

11. State and Props
• - Props: Read-only attributes passed from
parent to child
• - State: Local data storage that can be updated
in a component
• - Updating state re-renders the component

12. Lifecycle Methods
• - Mounting: constructor(),
componentDidMount()
• - Updating: shouldComponentUpdate(),
componentDidUpdate()
• - Unmounting: componentWillUnmount()

13. Popular Applications using React
• - Facebook
• - Instagram
• - WhatsApp Web
• - Netflix
• - Airbnb
• - Uber

14. Advantages of React
• - Fast performance with Virtual DOM
• - Component reusability
• - Strong community and ecosystem
• - Easy integration with other frameworks
• - Suitable for mobile apps using React Native

15. Conclusion
• React is a powerful library for building user
interfaces with speed and efficiency.
• With its modular architecture and growing
ecosystem, it is a top choice for modern web
development.
• Continue learning by building real-world
applications.