React Components: Functional vs. Class

React components are the building blocks of modern user interfaces, allowing developers to create modular, reusable, and maintainable code. Each component contains reusable bits of code that return HTML to build out user interfaces. We'll talk about all of that in this tutorial!

First, let's explore the two main types of React components and their usage in development environments.

Component Types

Functional Components

Functional components are stateless components defined as JavaScript functions. They receive props (React properties) as input and return JSX (JavaScript XML) to describe the user interface. These types of components are simpler and easier to read and test.

To simplify the explanation, here's an example of a functional component in action:

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

Class Components

Class components are stateful components that are defined as ECMAScript 6 (ES6) classes. They provide a way to build parts of an app that need to handle complex tasks or keep track of information.

Here's a usage example for a class component:

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

Rendering the Component Results

To render our newly created component in the application, we'll use the following syntax as a custom HTML pseudo-element:

import React from "react";
import ReactDOM from "react-dom/client";

const root = ReactDOM.createRoot(document.getElementById("root"));
root.render(<Hello name="Orangeable" />);

How Components Make Things Easier

• Modularity: Components promote a modular approach to building user interfaces by breaking down the UI into smaller, self-contained components, each responsible for a specific functionality or part of the UI.
• Reusability: Components are reusable, meaning they can be utilized throughout multiple parts of your application code to return similar output depending on its defined props. Reusability saves time and effort by eliminating the need to rewrite the same code for similar UI elements and improves consistency across your application.
• Data Flow: React enforces a unidirectional data flow, meaning the data flows from parent components to their associated child components through props, making it easier to track and manage data changes.
• Virtual DOM: React utilizes a virtual DOM (Document Object Model) to update the UI. When a component's state or props change, React calculates the minimum changes required to update the UI and applies them to the virtual DOM. This helps improve performance and reduces unnecessary re-rendering.

Conclusion

React components offer a powerful way to build interactive and dynamic user interfaces. Whether you're developing simple UI elements or complex applications, understanding and harnessing the power of React components is key to unlocking the library's full potential.