React Explained for Developers: How It Fits Into Full-Stack Apps

What Is React? ## How React Works ## React in the MVC Model ## Virtual DOM & One-Way Data Flow ## Prerequisites Before Learning React ## Components in React ## Working With State ## React Hooks (Overview) ## Creating a React App React is a library for building user interfaces. It runs in the browser as a Single Page Application (SPA), but it’s often used as part of a full-stack setup where it communicates with a server or API. It’s sometimes called a framework because of how powerful it is — comparable to Angular or Vue — but technically, React focuses on the view layer. A React app is typically a single HTML page. React itself doesn’t include routing — most projects use react-router-dom. In an MVC architecture: React acts as the View. Instead of separating logic and markup, React uses JSX, which allows JavaScript and markup to live together in a readable way. React uses a Virtual DOM, which allows it to: State is immutable — you don’t change it directly. You replace it using functions like setState() or useState(). You should be comfortable with: React isn’t hard — but it assumes JS fluency. React UIs are built from components. Modern React primarily uses function components with Hooks. Class components still exist, but they’re now considered legacy in most projects. State controls how components behave and render. There are two common types: State is always updated immutably. Advanced hooks (beyond basics): Templates let you quickly answer FAQs or store snippets for re-use. Are you sure you want to hide this comment? It will become hidden in your post, but will still be visible via the comment's permalink. Hide child comments as well For further actions, you may consider blocking this person and/or reporting abuse CODE_BLOCK: bash npx create-react-app my-app Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: bash npx create-react-app my-app CODE_BLOCK: bash npx create-react-app my-app - Created and maintained by Facebook - Runs in the browser - Compiles into a JavaScript bundle loaded once - Handles routing and updates client-side - Commonly paired with backend frameworks like Django - mounts into a root <div> - manages routing internally - updates only the parts of the UI that change - communicates with the server using JSON - UPDATE data - DELETE data - Model → data - Controller → routing & requests - update parts of the page without full reloads - stay fast and responsive - UI events → state updates - debugging easier - performance more predictable - JavaScript fundamentals - functions, arrays, objects - async/await & Promises - array methods like .map() and .forEach() - Fetch API & HTTP concepts - are reusable - manage their own state - compose together like puzzle pieces - Local state → belongs to one component - Global state → shared across components - useState → manage state - useEffect → handle side effects