Components and Props in React

1. Introduction

React is a popular JavaScript library for building user interfaces. At the core of React are components and props.

2. Components

Components are the building blocks of any React application. They allow you to split the UI into independent, reusable pieces.

2.1 Types of Components

• Functional Components: These are JavaScript functions that return React elements. They can accept props as arguments.
• Class Components: These are ES6 classes that extend from React.Component and must have a render method.

2.2 Example of a Functional Component

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

2.3 Example of a Class Component

class Greeting extends React.Component {
    render() {
        return <h1>Hello, {this.props.name}!</h1>;
    }
}
            

3. Props

Props, or properties, are a way to pass data from one component to another. They are read-only and help make components more dynamic.

3.1 Using Props

Props can be used to pass data into components. Here’s how you can use them:

function App() {
    return <Greeting name="John"/>;
}
            

3.2 Props Validation

Using PropTypes helps validate the data types of props passed to components.

import PropTypes from 'prop-types';

Greeting.propTypes = {
    name: PropTypes.string.isRequired
};
            

4. Best Practices

When working with components and props, consider the following best practices:

• Keep components small and focused.
• Use props to pass data and callbacks down to child components.
• Utilize PropTypes for props validation.
• Use defaultProps to define default values for props.

5. FAQ