React Basics

React is a JavaScript library for building user interfaces. Let’s explore the fundamental concepts that form the foundation of React development.

What is React?

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”.

Key Concepts

1. Components

Components are the building blocks of any React application. They are reusable pieces of code that return React elements describing what should appear on the screen.

function Welcome(props) {
  return <h1>Hello, {props.name}</h1>;
}

2. JSX

JSX is a syntax extension for JavaScript that allows you to write HTML-like code in your JavaScript files.

const element = <h1>Hello, world!</h1>;

3. Props

Props (short for properties) are read-only inputs to components. They are passed from parent to child components.

<Welcome name="John" />

4. State

State is a built-in object that stores property values that belong to the component. When state changes, the component re-renders.

const [count, setCount] = useState(0);

Getting Started

To start developing with React, you need to:

1. Install Node.js and npm
2. Create a new React project using Create React App or Vite
3. Understand the project structure
4. Start building components

Best Practices

1. Keep components small and focused
2. Use functional components with hooks
3. Follow the single responsibility principle
4. Write clean, readable code
5. Use proper naming conventions

Next Steps

Now that you understand the basics, you can move on to:

• Working with hooks
• Managing state
• Handling events
• Working with forms
• Making API calls