Exploring Node.js: The Ultimate Runtime for JavaScript Developers

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Exploring Node.js: The Ultimate Runtime for JavaScript Developers

What is Node.js?

Node.js is an open-source JS runtime that allows you to execute JavaScript code on the server side. It’s built on Chrome's V8 JavaScript engine.

Runtime?

The environment where JavaScript code is executed. It could be

On the server(backend)

In the browser(frontend)

V8 engine?

The V8 engine is an open-source JavaScript engine developed by Google. It is used to execute JavaScript code in various environments, most notably in the Google Chrome web browser.

Installing Node.js

Build from source

Using a package manager (brew, chocolat)

Using nvm

What is bun?

Like Node.js, Bun is a JavaScript runtime that allows you to execute JavaScript code on the server side.

Installing bun

Linux


curl -fsSL https://bun.sh/install | bash

Starting a Node.js project

To initialize a Node.js project locally,

Run the following command -


npm init -y

Exploring package.json

Writeing some code


let name="tushar";
console.log(name);

Run the code


node index.js

Add a script in package.json


"scripts":{
  "start":"node index.js"
},

Run npm run start

💡The full form of NPM is Node Package Manager.

It is a package manager for JavaScript, primarily used for managing libraries and dependencies in Node.js projects. NPM allows developers to easily install, update, and manage packages of reusable code

💡 package managers are an important concept in programming languages/runtimes. For eg the package manager of rust is cargo

Node.js provide you some internal packages also.

Internal Packages vs External Packages

Internal Packages

Some common ones include

fs - Filesystem

path - Path related functions

http - Create HTTP Servers (we’ll discuss this tomorrow)

fs package

The fs (Filesystem) package is used to read, write, update contents on the filesystem.


const fs=require("fs");
const path=require("path");

const filePath=path.join(__dirname,'a.txt');

fs.readFile(filePath, 'utf8',(err,data)=>{
if(err){
console.log(err);
}
else {
console.log(data);
}
})

External Packages

Some smart developers have written libraries like Chalk, Express, and many more, and published them on the NPM Registry. The NPM Registry is a vast collection of open-source JavaScript libraries and packages available for public use. It is managed by npm, Inc. This registry hosts millions of packages, ranging from simple utility functions to complex frameworks, allowing developers to easily integrate pre-built solutions into their projects.

Semantic Versioning Format

Every external package is updated incrementally. A specific version looks something like follows -


"chalk": "^5.3.0"

The format is as follows - MAJOR.MINOR.PATCH

MAJOR - Major version changes indicate significant updates or breaking changes.

MINOR - Minor version changes signify the addition of new features or improvements in a backward-compatible manner.

PATCH - Patch version changes include backward-compatible bug fixes or minor improvements that address issues without adding new features or causing breaking changes.

^ (Caret): Updates to the latest minor and patch versions (e.g., ^1.2.3 installs 1.2.x but not 2.x.x).

~ (Tilde): Updates only the patch version (e.g., ~1.2.3 installs 1.2.4 but not 1.3.0).

When you run


npm install <package-name>

npm fetches the specified package from the NPM registry, downloads it, and installs it into your project.

You can explore the registry and its packages at ‣

Try Fetching a Package from npm

Initializing a project


npm init -y

Make a file name index.js and Install external dependencies


npm install express

Write some code


const express = require('express')
const app = express()

app.get('/',(req, res)=> {
  res.send('Hello World')
})

app.listen(3000)

Run your code

Save this script in a file named index.js and execute it using:


node index.js

In your package.json, you define a start script like this:


"scripts": {
  "start": "node index.js"
}

Now you can run npm run start.

Use node index.js for simple, direct execution.

Use npm run start for standardized workflows in larger or team-based projects.

package-lock.json

When you run npm install, a file named package-lock.json is generated.

The package-lock.json records the exact versions of all dependencies and their dependencies (sub-dependencies) that are installed at the time when npm install was run.You should push the package-lock.json file to GitHub.

You lay a solid foundation for building efficient Node.js applications. With continuous learning and exploration, you can harness Node.js to create everything from simple scripts to complex backend systems.

Happy coding! 🚀