📚 React.js + Next.js Training Outline (11 Days)

This program is designed to give developers a deep dive into React.js and Next.js, from JavaScript essentials and React internals (JSX, Virtual DOM, Fiber, Reconciliation, Lifecycle) to TypeScript, build tools, and advanced Next.js features.

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Day 01: Introduction to React & Ecosystem

• What is React?
  • Origins, evolution & Meta’s role
  • Why React? The problem with direct DOM manipulation
• When to choose React?
  • SPAs, dashboards, UI-heavy apps
  • Strengths vs Angular, Vue, Svelte
• React Ecosystem overview
  • React DOM, React Native
  • State management (Context, Redux, Zustand)
  • Styling (Tailwind, CSS Modules, styled-components)
  • Developer tools (React DevTools, VSCode extensions)

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Day 02: JavaScript Advanced Refresher

• ES6+ Essentials (let, const, arrow functions, template literals)
• Objects & Arrays deep dive (map, filter, reduce, find)
• Spread/rest operators & destructuring
• Asynchronous JavaScript (Promises, async/await, fetch API)
• Closures, scopes, modules (import/export)

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Day 03: React Core Concepts (Part 1)

• JSX and React Elements
  • Writing HTML-like code in JS
  • JSX → transpiled by Babel → React.createElement()
  • React elements = plain JS objects (lightweight descriptions of UI)
• Rendering Basics
  • How React renders elements into the DOM (ReactDOM.createRoot)
• Components
  • Function components (preferred) vs Class components
  • Props → passing and validating props
• Hands-on: Simple counter app (JSX, props, rendering)

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Day 04: React Core Concepts (Part 2)

• State & Events
  • useState basics, updating state correctly
  • Event handling in React
• Virtual DOM
  • Concept of Virtual DOM as a lightweight JS representation
  • How React updates the Virtual DOM before touching the real DOM
• Reconciliation (Fiber Architecture)
  • Diffing algorithm → comparing old vs new trees
  • Efficient updates using Fiber scheduling
• Hands-on: Todo List app (state + list rendering)

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Day 05: React Lifecycle & Hooks

• Rendering & Committing
  • How React batches DOM updates
  • The commit phase → minimal real DOM updates
• Component Lifecycle
  • Mounting, updating, unmounting
  • Why lifecycle matters for performance
• Hooks
  • useEffect for side effects (fetch, subscriptions, cleanup)
  • Custom hooks for reusable logic
• Hands-on: API Fetch + cleanup example with useEffect

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Day 06: TypeScript Basics in React

• Why TypeScript? Benefits for React projects
• Primitive types & type inference
• Interfaces & type aliases
• Union & intersection types
• Typing React props & state (basic examples)
• Hands-on: Refactor Todo List with TypeScript types

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Day 07: TypeScript Advanced for React

• Generics (functions & components)
• Utility types (Partial, Pick, Omit, Record)
• Type narrowing & guards
• Typing hooks (useState, useReducer)
• Typing custom hooks
• Hands-on: Build a typed API fetcher hook

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Day 08: Compilers & Build Tools

• Why compilers/transpilers are needed (JSX, ESNext)
• Babel
  • JSX → JS transformation (React.createElement)
  • ESNext → ES5 transpilation
• Webpack
  • Entry, output, loaders, plugins
  • Dev vs Prod builds
• Modern alternatives: Vite, SWC, ESBuild
• Demo: Minimal React + Webpack config

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Day 09: Next.js (App Router – Routing Deep Dive)

• Page Router vs App Router (legacy vs modern)
• App Router fundamentals
  • app/ directory
  • Server vs Client Components
• File-based Routing System
  • page.tsx, layouts (layout.tsx), nested routes
  • Dynamic routes ([id]/page.tsx)
  • Catch-all routes ([...slug])
• Hands-on: Create a multipage Next.js app with nested layouts

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Day 10: Next.js – Rendering Models & Data Fetching

• Rendering strategies
  • CSR → Client-Side Rendering (default React)
  • SSR → Server-Side Rendering
  • SSG → Static Site Generation
  • ISR → Incremental Static Regeneration
• Data fetching in App Router
  • fetch() in Server Components
  • generateStaticParams
  • Combining SSR & SSG
• Hands-on: Blog app mixing static posts + dynamic user data

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Day 11: Next.js APIs, Deployment & Final Project

• API Routes in App Router (app/api/route.ts)
  • Route Handlers (GET, POST, PUT, DELETE)
  • Edge runtime basics
• SEO & Metadata (metadata object, head.js)
• Image & font optimization (next/image, next/font)
• Deployment options
  • Vercel (1-click deploy)
  • Self-hosting basics
• Final Project: Full blog app with dynamic routes, API integration & deployed to Vercel

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✅ Learning Outcomes

By the end of this program, developers will:

• Understand how React works internally (JSX, Virtual DOM, Fiber, reconciliation, commit phase)
• Build reusable, efficient components with hooks & lifecycle awareness
• Write strongly-typed React apps with TypeScript
• Understand compilers/build tools like Babel, Webpack, Vite
• Master the Next.js App Router, routing, SSR/CSR/SSG/ISR
• Build, optimize, and deploy a real-world Next.js application

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