Introduction And Installation Of React Js

Introduction of React Js
React is a JavaScript library created by Facebook for building user interfaces, especially for web applications. It lets developers build reusable UI components that update efficiently when data changes. Instead of reloading a whole page, React updates only the parts that change, making apps faster. In simple terms, React helps create dynamic, interactive, and smooth web experiences easily.

Key Features of React.js

Component-Based Architecture

UI is broken down into reusable components.

Each component manages its own state and logic.

Virtual DOM

React uses a virtual DOM to efficiently update and render components.

It compares the virtual DOM with the real DOM and updates only the parts that changed.

Declarative Syntax

You describe what you want to see, and React takes care of the how.

This makes code more predictable and easier to debug.

JSX (JavaScript XML)

A syntax extension that allows you to write HTML-like code in JavaScript.

Makes writing UI components more intuitive.

Unidirectional Data Flow

Data flows from parent to child components, making the app easier to understand and maintain.

Hooks (React 16.8+)

Functions like useState, useEffect, etc., allow you to use state and lifecycle features in functional components

It helps in remember things (like tasks) and react to changes (like showing reminders)

Important Extensions:-

Chrome Extension

React Developer Tools

VS Code Extension

Thunder Client

ES7 React/Redux/GraphQL/React-Native

Bracket pair colorization

Auto Rename Tag

Links

Node.js official website: https://nodejs.org

React official website learning articles: https://react.dev/learn

Commands for creating & running a React app

# create a new React project (using NPX)
npx create-react-app my-app     # creates folder “my-app” with boilerplate :contentReference[oaicite:5]{index=5}

cd my-app                        # change into the project folder

npm start                        # start the development server and view the app in browser :contentReference[oaicite:6]{index=6}