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Step-by-Step Guide to Run JavaScript with Node js

Run JavaScript with Node js
Website Development
10 min read

Ready to learn how to run JavaScript with Node js? In this blog, we’ll guide you through all the essential information you need to understand. Whether you’re a newcomer to technology or an industry expert, we’ll guide you through every stage. Get ready to explore the world of server-side JavaScript and unlock new possibilities with Node.js!

Getting Started with Node.js

Getting Started with Node.js

Node.js is a freely available JavaScript runtime environment that works across different platforms. It allows developers to run JavaScript Node code outside of a web browser. Here are some important points about Node.js:

  1. JavaScript Runtime: Nodejs run JavaScript V8 engine, which is also the core engine behind Google Chrome. However, instead of running within the browser, Node.js JavaScript operates as a standalone runtime on servers or local machines.
  2. Performance: One of Node.js’ strengths is its performance. By leveraging the V8 engine, it achieves high execution speeds. This makes it perfect for different kinds of projects.
  3. Single-Threaded, Non-Blocking: Unlike traditional server-side technologies, Node.js operates in a single process with an event-driven, non-blocking I/O model. When an I/O operation (e.g., reading from a network, accessing a database, or working with the filesystem) occurs, Node.js doesn’t block the entire thread. Instead, it continues processing other tasks until the I/O operation completes.
  4. Asynchronous I/O: Node.js provides asynchronous I/O primitives in its standard library. This means that JavaScript code can perform I/O operations without blocking the execution flow. Libraries in Node.js are designed using non-blocking paradigms, making blocking behavior the exception rather than the norm.
  5. Concurrent Connections: Node.js can handle thousands of concurrent connections with a single server. Managing thread concurrency is not a concern, reducing the risk of bugs related to thread synchronization.
  6. Frontend Developers’ Advantage: Node.js allows frontend developers who already know JavaScript to write server-side code without learning a completely different language. You can use the latest ECMAScript standards without waiting for users to update their browsers.

Why Use Node.js?

Here are a few reasons why you might want to think about run javascript with node js:

  1. Unified Language: If you’re already comfortable with JavaScript for frontend development, Node.js lets you use the same language for both client-side and server-side development. This consistency streamlines your workflow.
  2. Scalability: Node.js’ non-blocking architecture makes it well-suited for scalable applications. It efficiently handles concurrent requests, making it ideal for real-time applications, APIs, and microservices.
  3. Rich Ecosystem: Node.js has a vast ecosystem of packages (available via npm) that simplify development. Whether you need to work with databases, build APIs, or handle authentication, there’s likely a package available.
  4. Community Support: Node.js has an active community, which means you can find tutorials, documentation, and help easily.

How to Install Node.js?

You can install Node.js using different methods:

  1. Official Installer: The easiest way is to download the official Node.js installer from the Node.js website. Pick the Long-Term Support (LTS) version and then just follow the installation steps.
  2. Package Managers
    • npm: npm (Node Package Manager) comes bundled with Node.js. It simplifies package management.
    • nvm: nvm (Node Version Manager) allows you to switch Node.js versions easily and test your code with different versions. Check out nvm on GitHub for more details.
  3. Operating System-Specific Guides

Read More: Nodejs Authentication

Running JavaScript Files with Node.js CLI

To execute a Node run JavaScript file using the Node.js command-line interface (CLI), follow these steps:

  1. Create a JavaScript File
    • First, create a .js file containing your JavaScript code. For example, let’s create a file named myScript.js.
  2. Open Terminal or Command Prompt:
    • Go to the folder where your JavaScript file is saved.
  3. Run the File

Type the following command in the terminal:

node myScript.js
  • Replace myScript.js with the actual filename.
  1. Output
    • If your script produces any output (e.g., logs, console messages), it will be displayed in the terminal.

Learn More About: Nodejs And TypeScript

Different Ways to Execute JavaScript Code in Node.js

  1. Interactive Mode (REPL)
    • Node.js provides an interactive mode called the Read-Eval-Print Loop (REPL). Launch it by typing node in the terminal without specifying a file.
    • You can directly type JavaScript code and see the results interactively.
  2. Using require in Other Files
    • You can split your code into multiple files and use required to include them in your main script.

For example:

// myModule.js
module.exports = {
    greet: () => ‘Hello from myModule!’
};

 

// main.js
const myModule = require(‘./myModule’);
console.log(myModule.greet());
  1. Running Scripts with Arguments
    • You can pass command-line arguments to your Node.js script using process.argv.

For example:

// myArgs.js
console.log(‘Arguments:’, process.argv.slice(2));

 Run it as:

node myArgs.js arg1 arg2

When to Use Node.js for Running JavaScript Scripts

Consider using Node.js in the following scenarios:

Server-Side Applications

  • Node.js is excellent for building server-side applications, APIs, and microservices.
  • Its non-blocking architecture allows for handling concurrent requests efficiently.
  1. Real-Time Applications
    • Node.js works great for real-time applications such as chat, gaming, and collaborative tools.
    • WebSockets and libraries like Socket.io make real-time communication easy.
  2. Command-Line Tools
    • Node.js is great for creating command-line tools and utilities.
    • You can build custom scripts for tasks like data processing, file manipulation, or automation.
  3. Single-Page Applications (SPAs)
    • If you’re building SPAs using frameworks like React, Vue, or Angular, Node.js can serve as the backend.

Remember that Node.js is not ideal for CPU-intensive tasks due to its single-threaded nature. For CPU-bound operations, consider using other languages or technologies.

Run JavaScript in Node

To run JavaScript in Node for simple Node.js application, consider the following “Hello World” example:

const http = require(‘node:http’);

const hostname = ‘127.0.0.1’;
const port = 3000;

const server = http.createServer((req, res) => {
    res.statusCode = 200;
    res.setHeader(‘Content-Type’, ‘text/plain’);
    res.end(‘Hello World’);
});

server.listen(port, hostname, () => {
    console.log(`Server running at <http://$>{hostname}:${port}/`);
});
  1. Save the above code as a server.js file.
  2. Run node server.js in your terminal.
  3. Visit http://127.0.0.1:3000/ in your browser to see the “Hello World” message.

In this example, we’re making an HTTP server with Node.js. When a request is received, the server responds with “Hello World.” The non-blocking nature of Node.js JavaScript ensures efficient handling of multiple requests simultaneously. Here’s a simple use of run javascript with node js. 

Where Can Node.js Be Used for Server-Side Scripting?

Nodejs used for Server-Side Scripting

  1. API Development
    • Node.js is commonly used to build RESTful APIs and GraphQL endpoints.
    • Express.js, a popular Node.js JavaScript framework, simplifies API development.
  2. Real-Time Applications
    • Chat applications, online gaming, and collaborative tools benefit from Node.js’ event-driven architecture.
    • Libraries like Socket.io enable real-time communication.
  3. Microservices
    • Node.js is ideal for microservices architecture due to its lightweight nature and efficient handling of concurrent requests.
  4. Single-Page Applications (SPAs)
    • Node.js serves as the backend for SPAs built using frameworks like React, Angular, or Vue.
  5. Streaming Services
    • Media streaming platforms, live video broadcasting, and file upload/download services can utilize Node.js JavaScript.

Read More: Top Nodejs Libraries: Your Essential Toolkit

Common Trouble Errors in Node.js

  1. Unhandled Exceptions in Streams
    • Streams are essential for reading from and writing to data sources that don’t wait for tasks to complete, like files, sockets, and HTTP requests.
    • If you don’t attach an error handler to a stream, unhandled exceptions can crash your application.
    • Always attach an error event handler to catch and handle stream errors.
  2. ECONNRESET
    • This exception occurs when a TCP connection is unexpectedly terminated by the client or server.
    • It can happen during external requests or when responding to a client request after the connection is closed.
  3. Memory Leaks (Heap Out of Memory)
    • Node.js has a default memory limit for the V8 heap space.
    • Profile your application to identify memory leaks and refactor code for efficiency.
    • Use -max-old-space-size to adjust the heap memory limit.

Debugging JavaScript in Node.js

  1. Enable Inspector
    • Start Node.js with the -inspect switch to listen for a debugging client.
    • By default, it listens at 127.0.0.1:9229.
    • Use tools like Chrome DevTools or Microsoft Edge to connect to the Inspector.
  2. Command-Line Debugging
    • Use node inspect your-script.js to start a minimal CLI debugger.
    • Set breakpoints, inspect variables, and navigate through your code.
  3. Try-Catch for Synchronous Code
    • Wrap synchronous code interacting with streams in a try-catch block.
    • Handle errors effectively to prevent crashes.

Get in Touch with Artoon Solutions

Artoon Solutions is one of the top-notch Node js development agency. We have a team of experienced developers and a proven track record of more than 14+ years delivering high-quality solutions. We are committed to helping businesses to drive innovation and growth through our Nodejs development services to their needs.

Wrapping Up!

At the end when you have to run JavaScript with Node js required having enough knowledge of dependency management, leveraging advanced features, and adhering to best practices are essential for effective Node.js development. These principles ensure code quality, maintainability, and performance, contributing to successful backend projects. To create scalable, secure and efficient applications, Hire Nodejs programmers from Artoon Solutions.

FAQs

1). Can I use JavaScript in node JS?

Yes, you can use JavaScript in Node.js.

2). How to run a JavaScript code?

To run JavaScript code, you can use Node.js command-line interface (CLI) by typing node filename.js.

3). How to run JavaScript with Node js in Visual Studio Code?

You can run JavaScript with Node in Visual Studio Code by installing the Node.js extension and using the integrated terminal.

4). Does node JS allow you to run JavaScript on the server?

Yes, Node.js allows you to run JavaScript on the server.

5). How do I run a JavaScript script from node?

To run a JavaScript script from Node.js, use the command node filename.js in your terminal.

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