Using NPM to Install Packages in Node.js – The Ultimate Guide

NodeJs

"Node.js is like a magical kitchen for JavaScript—originally, it could only cook in the browser, but now it can build backends, manage servers, and even make coffee... if there's an npm package for it!"

 

So, you’ve just started with Node.js, and you keep hearing about npm (Node Package Manager).

But what is npm?

Imagine npm as a giant supermarket for JavaScript packages.

• Want to build a web server? There’s a package for that!
• Need to scrape a website? There’s a package for that too!
• Looking for a package that tells dad jokes? You guessed it—npm has one!

In this guide, you’ll learn:

• What is npm and why do you need it?
• How to install, update, and remove packages.
• The difference between global and local installations.
• Some fun and useful npm commands.

Let’s get started!

What is npm?

npm (Node Package Manager) is the default package manager for Node.js.
It allows you to install, update, and manage JavaScript libraries (a.k.a. "packages" or "modules").

npm is included with Node.js, so if you’ve installed Node.js, you already have npm!

Check if npm is installed:

npm -v

Output:

9.8.1  (Your version may differ)

Congrats! You’re ready to use npm!

Installing Packages with npm

1. Installing a Package Locally (Project-Specific)

npm install package-name

Example: Installing express

npm install express

What happens?

• npm creates a node_modules/ folder (if it doesn’t exist).
• It downloads and saves express inside node_modules/.
• It updates package.json (if it exists).

2. Installing a Package Globally (Available Everywhere)

npm install -g package-name

Example: Installing nodemon globally

npm install -g nodemon

What happens?

• The package is installed system-wide.
• You can use it from any directory.

When to install globally?

• CLI tools like nodemon, http-server, or npm-check-updates.

Understanding package.json

What is package.json?

• It’s like a manifest file for your project.
• It lists dependencies, scripts, and metadata.

Creating package.json (The Easy Way)

npm init -y

Example package.json file:

{
  "name": "my-app",
  "version": "1.0.0",
  "description": "My first Node.js app",
  "dependencies": {
    "express": "^4.18.2"
  },
  "devDependencies": {
    "nodemon": "^2.0.22"
  }
}

Installing Different Types of Dependencies

1. Installing a Production Dependency (dependencies)

npm install lodash

Adds "lodash" under "dependencies" in package.json.

2. Installing a Development Dependency (devDependencies)

npm install jest --save-dev

Used for testing tools, linters, or build tools.

3. Installing an Exact Version

npm install moment@2.29.4

Installs a specific package version.

4. Installing Multiple Packages at Once

npm install express mongoose cors dotenv

Installs multiple packages in one command.

Updating and Removing Packages

1. Updating All Packages

npm update

Updates all dependencies to the latest minor/patch versions.

2. Updating a Specific Package

npm update lodash

Updates only lodash.

3. Removing a Package

npm uninstall package-name

Example:

npm uninstall express

Removes the package from node_modules and package.json.

Checking Installed Packages

1. List Installed Packages (Locally)

npm list

Shows installed packages inside your project.

2. List Installed Packages (Globally)

npm list -g --depth=0

Shows all globally installed packages.

 3. Find Outdated Packages

npm outdated

Lists packages that have newer versions available.

Running Scripts with npm

1. Adding Custom Scripts to package.json

Modify package.json:

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

2. Running the Script

npm run dev

Executes nodemon index.js.

Fun and Useful npm Packages

1. Create Cool ASCII Banners

npm install cowsay

Use it in your project:

const cowsay = require('cowsay');
console.log(cowsay.say({ text: "I ❤️ Node.js!" }));

Output:

  I ❤️ Node.js!
        \   ^__^
         \  (oo)\_______
            (__)\       )\/\
                ||----w |
                ||     ||

2. Get Random Dad Jokes

npm install one-liner-joke

Example:

const joke = require('one-liner-joke');
console.log(joke.getRandomJoke().body);

Laugh while coding!

 

 Conclusion

 Now you’re an npm master!

• You know how to install, update, and remove packages.
• You understand global vs. local installation.
• You can write custom scripts in package.json.

 Next step? Try exploring fun npm packages like chalk, figlet, or ora to make your CLI apps more exciting!

Happy coding!