Topic 3

NPM Official Website: NPMJS

Youtube Resources: NPM

Basics of NPM and NPM Pacages

What is NPM?

NPM is a package manager for Node.js packages, or modules if you like. npmjs hosts thousands of free packages to download and use.

The NPM program is installed on your computer when you install Node.js

What is a Package?

A package in Node.js contains all the files you need for a module. Modules are JavaScript libraries you can include in your project.

Downloading a Package

Open the command line interface and tell NPM to download the package you want.

npm install package_name

Using a Package

Once the package is installed, it is ready to use.

Include the package-name the same way you include any other module:

var package-name = require('package-name');

Some useful and famous packages

• express
• axios
• body-parser
• lodash
• mongoose
• nodemailer
• passport
• multer
• dotenv
• nodemon, etc…

Things to try

Try npm init (In a separate folder)

npm init can be used to set up a new or existing npm package. this creates a package.json file where all your data like installed packages, custom scripts, versions, etc.

npm init

After npm init it asks for various things just press enter till it isn’t done. Now a pacakge.json is created inside your folder.

for e.g. Now I want to download a package called “mongoose” so I do

npm install mongoose
// or
npm i mongoose

Now you have downloaded and installed your first package! NPM creates a folder named node_modules, where the package will be placed. All packages you install in the future will be placed in this folder. Also mongoose is added inside package.json you can check.