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1 of 44⚛️ Introduction to ReactJS
📌 What is React?
React is a JavaScript library for building user interfaces, mainly used for creating single-page applications. It allows developers to build reusable UI components and is free & open-source.
📘 Overview
React is a declarative, efficient, and flexible JavaScript library for building user interfaces. It lets you compose complex UIs from small and isolated pieces of code called Components.
- React was created by Facebook
- It's used for building complex and interactive web and mobile UI
- It follows component-based architecture
- It uses virtual DOM for better performance
⚙️ How Does React Work?
React creates a virtual DOM in memory. Instead of manipulating the browser's DOM directly, React performs all changes in the virtual DOM first. Then it efficiently updates only the changed parts in the actual DOM, improving performance.
🌐 Popular Applications Using React
- Facebook – Popular social media application.
- Instagram – Popular photo sharing application.
- Netflix – Popular media streaming application.
- Code Academy – Popular online training platform.
- Reddit – Popular content sharing application.
💡 Why Use React?
- Large community on GitHub and active support.
- Component-based architecture.
- Efficient DOM updates.
- Declarative approach for UI building.
📝 Declarative Approach
In a declarative approach, you describe what you want the UI to look like, rather than giving step-by-step instructions on how to change it.
With React, you tell JavaScript what you want to be done, and React takes care of performing the required steps efficiently.