node js file extension with code examples

When it comes to web development, Node.js has become one of the most popular platforms. Node.js allows developers to work with server-side applications and write code that can be executed on the server. Node.js supports a variety of file extensions, each with its own specific purpose. In this article, we will explore some of the most common Node.js file extensions and provide some code examples to help you better understand how to use them.

.js File Extension

The .js file extension is the most common file extension used in Node.js. It is used for JavaScript code files that are used to execute logic on the server side. JavaScript code can be executed on the client-side as well, but Node.js allows JavaScript to be executed on the server side. In .js files, you can define functions, classes, and objects that are used to execute specific logic on the server side.

Here is an example of a basic .js file:

function myFunction() {
  console.log("Hello, World!");
}

myFunction();

In this example, we define a function called myFunction that logs "Hello, World!" to the console. We then call the function using myFunction().

.json File Extension

The .json file extension is used for data files that contain JSON (JavaScript Object Notation) formatted data. JSON is a lightweight data interchange format that is easy for humans to read and write, and easy for machines to parse and generate. JSON is often used for APIs, configuration files, and data storage.

Here is an example of a basic .json file:

{
  "name": "John",
  "age": 30,
  "city": "New York"
}

In this example, we define a JSON object with three key-value pairs. This is a simple example, but JSON can handle complex nested objects and arrays.

.html File Extension

The .html file extension is used for HTML (Hypertext Markup Language) files that define the structure and content of web pages. HTML is the standard markup language for creating web pages and is often paired with CSS (Cascading Style Sheets) and JavaScript to create dynamic and interactive web pages.

Here is an example of a basic HTML file:

<!DOCTYPE html>
<html>
<head>
	<title>My Website</title>
</head>
<body>
	<h1>Hello, World!</h1>
</body>
</html>

In this example, we define an HTML page with a title of "My Website" and a heading that reads "Hello, World!".

.css File Extension

The .css file extension is used for CSS (Cascading Style Sheets) files that define the visual appearance of web pages. CSS is used to control the layout, color, font, and other visual aspects of web pages.

Here is an example of a basic CSS file:

body {
  background-color: #eee;
}

h1 {
  color: blue;
}

In this example, we define CSS styles for the body and h1 tags. We set the background color of the body to light gray (#eee) and the color of h1 headings to blue.

Conclusion

Node.js supports a variety of file extensions that are used for different purposes. In this article, we explored some of the most common file extensions used in Node.js and provided some code examples to help you better understand how to use them. By understanding these file extensions, you can become a more effective Node.js developer and create powerful server-side applications.

let's dive a bit deeper into some of the previous topics we covered in the article.

.js File Extension

JavaScript is a dynamic, high-level, and interpreted programming language that is used to create interactive and dynamic websites. The .js file extension is used to write server-side applications that can include features like handling HTTP requests and responses, file systems, and databases.

Node.js is built on top of the Google V8 engine and can be used to run JavaScript code on the server. Node.js is often used for building real-time applications like chat applications, multiplayer games, and video streaming applications.

Here is an example where a .js file can be used to create a simple HTTP server that listens to a port and sends a response:

const http = require('http');

const PORT = 3000;

const server = http.createServer((req, res) => {
  res.writeHead(200, {"Content-Type": "text/plain"});
  res.end("Hello, World!
");
});

server.listen(PORT, () => {
  console.log(`Server running on port ${PORT}`);
});

In this example, we use the http module to create an HTTP server that listens on port 3000. When a request is made, the server sends a response with a status code of 200 (OK) and the message "Hello, World!".

.json File Extension

JSON is a lightweight, text-based data interchange format that is often used for data transfer between applications. JSON is easy for humans to read and write, and easy for machines to parse and generate.

The .json file extension is often used for configuration files, data storage, and APIs. With the help of the fs module in Node.js, we can read and write data to and from .json files.

Here is an example where we can use a .json file to store and retrieve data:

// data.json
{
  "users": [
    {
      "id": 1,
      "name": "John Doe",
      "email": "john@example.com"
    },
    {
      "id": 2,
      "name": "Jane Doe",
      "email": "jane@example.com"
    }
  ]
}
// app.js
const fs = require('fs');

const data = fs.readFileSync('data.json');
const parsedData = JSON.parse(data);

console.log(parsedData.users[0].name); // "John Doe"

In this example, we read data from the data.json file using the readFileSync() function from the fs module. The data is then parsed into a JavaScript object using JSON.parse(). We can then access the data in the object using dot notation.

.html and .css File Extensions

HTML and CSS are two building blocks of web development. HTML defines the structure and content of a webpage while CSS defines the visual appearance of a webpage. The .html and .css file extensions are used to create web pages.

Here is an example of a simple webpage that uses HTML and CSS:

<!DOCTYPE html>
<html>
<head>
	<title>My Website</title>
	<link rel="stylesheet" href="style.css">
</head>
<body>
	<header>
		<h1>My Website</h1>
		<nav>
			<ul>
				<li><a href="#">Home</a></li>
				<li><a href="#">About</a></li>
				<li><a href="#">Contact</a></li>
			</ul>
		</nav>
	</header>
	
	<main>
		<section>
			<h2>Welcome to my website</h2>
			<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit.</p>
		</section>
	</main>
	
	<footer>
		<p>&copy; 2021 My Website.</p>
	</footer>
</body>
</html>
/* style.css */
body {
  font-family: Arial, sans-serif;
  margin: 0;
}

header {
  background-color: #333;
  color: #fff;
  padding: 1em;
}

nav ul {
  list-style-type: none;
  margin: 0;
  padding: 0;
}

nav li {
  display: inline-block;
  margin-right: 1em;
}

nav a {
  color: #fff;
  text-decoration: none;
}

main {
  margin: 2em;
}

section {
  margin-bottom: 2em;
}

footer {
  background-color: #333;
  color: #fff;
  padding: 1em;
  text-align: center;
}

In this example, we create a simple webpage with a header, navigation bar, main section, and footer. We use CSS to style the elements and make the webpage look visually appealing.

Conclusion

Node.js is a powerful platform for building server-side applications, and it supports a variety of file extensions for different purposes. The .js file extension is used to write JavaScript code for server-side applications, while .json is used for data storage and transfer. HTML and CSS are used to create web pages, and they rely on the .html and .css file extensions. By understanding these file extensions, you can become a more effective Node.js developer and create powerful server-side applications.

Popular questions

Sure, here are the answers to 5 questions for ‘Node.js File Extension with Code Examples’:

Q1. What is the purpose of the .js file extension in Node.js?
A1. The .js file extension is used for JavaScript code files that are used to execute logic on the server side in Node.js.

Q2. What is JSON, and what is the purpose of the .json file extension in Node.js?
A2. JSON is a lightweight data interchange format that is easy for humans to read and write and easy for machines to parse and generate. The .json file extension is used for data files that contain JSON-formatted data in Node.js, which is often used for APIs, configuration files, and data storage.

Q3. What is the purpose of the .html file extension in Node.js?
A3. The .html file extension is used for HTML files that define the structure and content of web pages in Node.js.

Q4. What is the purpose of the .css file extension in Node.js?
A4. The .css file extension is used for CSS files that define the visual appearance of web pages in Node.js.

Q5. How can we use the .js file extension to create a simple HTTP server that listens to a port and sends a response in Node.js?
A5. Here’s an example of how you can use the .js file extension to create a simple HTTP server in Node.js:

const http = require('http');

const PORT = 3000;

const server = http.createServer((req, res) => {
  res.writeHead(200, {"Content-Type": "text/plain"});
  res.end("Hello, World!
");
});

server.listen(PORT, () => {
  console.log(`Server running on port ${PORT}`);
});

In this code snippet, we use the http module to create an HTTP server that listens on port 3000. When a request is made, the server sends a response with a status code of 200 (OK) and the message "Hello, World!".

Tag

"Node.js Scripts"

Throughout my career, I have held positions ranging from Associate Software Engineer to Principal Engineer and have excelled in high-pressure environments. My passion and enthusiasm for my work drive me to get things done efficiently and effectively. I have a balanced mindset towards software development and testing, with a focus on design and underlying technologies. My experience in software development spans all aspects, including requirements gathering, design, coding, testing, and infrastructure. I specialize in developing distributed systems, web services, high-volume web applications, and ensuring scalability and availability using Amazon Web Services (EC2, ELBs, autoscaling, SimpleDB, SNS, SQS). Currently, I am focused on honing my skills in algorithms, data structures, and fast prototyping to develop and implement proof of concepts. Additionally, I possess good knowledge of analytics and have experience in implementing SiteCatalyst. As an open-source contributor, I am dedicated to contributing to the community and staying up-to-date with the latest technologies and industry trends.
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