Introduction to React

React is a JavaScript library for building user interfaces, primarily for single-page applications.

React is developed and maintained by Facebook and allows developers to create reusable UI components and manage the state of applications effectively. It emphasises a declarative programming style, making it easier to design interactive and dynamic user experiences.

The terms React and ReactJS are interchangeably used in general, and in these tutorials.

Key Features of React

  • Component-Based Architecture: Build encapsulated components that manage their own state.
  • Virtual DOM: Updates only the necessary parts of the DOM for improved performance.
  • Declarative Syntax: Describe what the UI should look like, and React handles the updates.
  • Unidirectional Data Flow: Ensures predictable data management.
  • Extensibility: Integrates seamlessly with other libraries and frameworks.

React is widely used in modern web development, powering platforms like Facebook, Instagram, and Airbnb.

Prerequisites

Before diving into React, you should have a solid understanding of the following:

1. HTML

  • Structure of web pages.
  • Familiarity with elements, attributes, and semantic HTML.

2. CSS

  • Styling basics, including selectors, box model, and responsive design.
  • Understanding of Flexbox and Grid layout systems.

3. JavaScript

  • ES6+ features like arrow functions, classes, destructuring, and modules.
  • DOM manipulation and event handling.
  • Basic understanding of asynchronous JavaScript (promises, async/await).

4. Node.js and npm

  • Setting up and running Node.js applications.
  • Using npm or yarn to manage packages.

Plan for Learning React

Here’s a roadmap to help you master React systematically:

Phase 0: Getting Started

  1. Install React on MacOS
  2. Install React on Windows

Phase 1: React Basics

  1. Introduction to JSX.
  2. Components and Props.
  3. State and Lifecycle.
  4. Handling Events.
  5. Conditional Rendering.
  6. Lists and Keys.
  7. Forms in React.

Phase 2: Intermediate React

  1. Lifting State Up.
  2. Composition vs. Inheritance.
  3. Thinking in React.
  4. Hooks Overview (useState, useEffect).
  5. Context API.
  6. React Router Basics.

Phase 3: Advanced React

  1. Custom Hooks.
  2. Error Boundaries.
  3. Code Splitting and Lazy Loading.
  4. Optimizing Performance.
  5. Refs and Forwarding Refs.

Phase 4: Ecosystem and Tools

  1. State Management with Redux or Zustand.
  2. Testing React Applications (Jest, React Testing Library).
  3. Styled Components or CSS-in-JS.
  4. Server-Side Rendering (SSR) with Next.js.
  5. TypeScript with React.

Phase 5: Project-Based Learning

  1. Build small projects (e.g., Todo App, Calculator).
  2. Create a medium-scale project (e.g., Blog Platform, E-commerce UI).
  3. Develop a full-scale application with a backend (e.g., Chat App, Dashboard).