In this inaugural article of the "Mastering React with Next.js: A Developer's Guide" series, we'll embark on a journey to understand the core concepts of React, a powerful JavaScript library for building user interfaces. Our focus will be on setting up the development environment and creating your first React component using Next.js, a robust React framework.

Introduction to React

React is a JavaScript library developed by Facebook for building user interfaces, particularly single-page applications where efficient data updating and rendering are crucial. It allows developers to create reusable UI components, leading to more manageable and scalable code.

Why Use Next.js?

As of early 2025, Create React App (CRA) has been deprecated, making way for modern alternatives like Next.js. Next.js offers powerful features, including:

File-based routing: Simplifies route management without additional configuration.
Server-side rendering (SSR): Enhances performance and SEO by rendering pages on the server.
Static site generation (SSG): Generates static HTML at build time for faster page loads.
Built-in API routes: Enables serverless function creation directly within your app.

With these advantages, Next.js is the preferred choice for building React applications.

Setting Up the Development Environment

Before diving into React, ensure your development environment is ready:

Node.js and npm: Next.js relies on Node.js and npm (Node Package Manager) for managing packages. Download and install them from the official Node.js website.
Code Editor: Choose a code editor like Visual Studio Code, which offers excellent support for JavaScript and React.

Creating a New Next.js Application

To set up a new project with Next.js, follow these steps:

Install Next.js:

Open your terminal and run:
```
npx create-next-app@latest my-first-next-app
```
This command creates a new directory named my-first-next-app with all the necessary files and dependencies.
Navigate to the Project Directory:
```
cd my-first-next-app
```
Start the Development Server:
```
npm run dev
```
Your application will run at http://localhost:3000/, and any changes you make will automatically reload the page.

Understanding JSX

JSX (JavaScript XML) is a syntax extension for JavaScript that resembles HTML. It's used in React to describe what the UI should look like. JSX makes the code more readable and easier to write. For example:

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

This JSX code is transformed into standard JavaScript by tools like Babel.

Creating Your First Component

Components are the building blocks of a React application. A component can be a function or a class that returns a React element. Here's how to create a simple functional component in Next.js:

Define the Component

Create a new folder named components in your project directory.
```
mkdir components
```

Create a new file named Greeting.js inside the components folder:

const Greeting = () => {
  return <h1>Welcome to React with Next.js!</h1>;
};

export default Greeting;

Use the Component

In the pages/index.js file, import and use the Greeting component:

import Greeting from '../components/Greeting';

export default function Home() {
  return (
    <div>
      <Greeting />
    </div>
  );
}

Save your changes and visit http://localhost:3000. You should see "Welcome to React with Next.js!" displayed on the page.

Adding Styles to Your Component

Next.js supports CSS Modules by default, making it easy to style components. Let’s add some styles to Greeting:

Create a new file called Greeting.module.css in the components folder:

.title {
  font-size: 2rem;
  color: #0070f3;
  text-align: center;
  margin-top: 50px;
}

Update Greeting.js to use these styles:

import styles from './Greeting.module.css';

const Greeting = () => {
  return <h1 className={styles.title}>Welcome to React with Next.js!</h1>;
};

export default Greeting;

Reload the page, and you’ll see the styled component.

Conclusion

In this article, we've set up the development environment and created our first React component using Next.js. Understanding these basics is crucial as we delve deeper into React's capabilities in the upcoming articles. Stay tuned as we explore components, props, state, and more in the next installments of this series.

Introduction to React: Building Your First Component with Next.js