React Fundamentals – Beginner Guide to Components, JSX & State

Understanding React fundamentals is essential before working with React Native or modern frontend frameworks.

What is React

React is a library used to build user interfaces, especially single-page applications.

🔸 Developed and maintained by Meta (Facebook)
🔸 Focuses on component-based architecture
🔸 Updates UI efficiently using a virtual DOM
🔸 Widely used in web and mobile development

React helps developers build dynamic applications with better performance.

Components in React Native

Components are the building blocks of React and React Native applications.

🔸 Each component represents a part of the UI
🔸 Components can be reused across the app
🔸 Helps break complex UI into smaller pieces
🔸 Makes code easier to manage and test

In React Native, everything you see on the screen is a component.

Functional Components

Functional components are simple JavaScript functions that return UI.

🔸 Easier to write and understand
🔸 Use hooks to manage state and lifecycle
🔸 Preferred over class components in modern React
🔸 Help keep code clean and readable

Functional components are the standard approach in new React projects.

JSX Explained

JSX is a syntax extension used in React to write UI code.

🔸 Looks similar to HTML
🔸 Allows writing UI inside JavaScript
🔸 Makes code more readable and expressive
🔸 Compiled into regular JavaScript

JSX helps developers visualize the UI while coding.

Props and State

Props and state are used to manage data in React components.

🔸 Props are used to pass data from parent to child components
🔸 Props are read-only
🔸 State is used to manage dynamic data inside a component
🔸 State changes cause the UI to re-render

Understanding props and state is key to building interactive applications.

Component Lifecycle

The component lifecycle describes different stages of a component’s life.

🔸 Component creation
🔸 Component update
🔸 Component removal

In modern React, lifecycle behavior is managed using hooks like useEffect.

Lifecycle understanding helps manage side effects like API calls and timers.

Why React Fundamentals Matter

React fundamentals form the base for advanced development.

🔸 Essential for React Native development
🔸 Required for frontend and mobile roles
🔸 Helps build scalable and maintainable apps
🔸 Important for interviews and real projects

Strong fundamentals make learning advanced concepts much easier.