Node.js — NPM

What is npm?

npm is the default package manager for Node.js.

Basic Commands

npm init                    # Initialize project
npm install express         # Install package
npm install express@4.18    # Install specific version
npm install -D nodemon      # Install dev dependency
npm uninstall express       # Remove package
npm update                  # Update packages

package.json

{
  "name": "my-app",
  "version": "1.0.0",
  "description": "My application",
  "main": "index.js",
  "scripts": {
    "start": "node index.js",
    "dev": "nodemon index.js",
    "test": "jest"
  },
  "dependencies": {
    "express": "^4.18.2"
  },
  "devDependencies": {
    "nodemon": "^3.0.0"
  }
}

npm Scripts

{
  "scripts": {
    "start": "node index.js",
    "dev": "nodemon index.js",
    "build": "webpack --mode production",
    "test": "jest --coverage"
  }
}

npm start
npm run dev
npm run build

package-lock.json

Locks exact versions of dependencies for reproducible builds.

npm Registry

npm search express
npm info express
npm view express version

Mini Practice

1. Initialize a new project
2. Install a package
3. Create npm scripts
4. Update packages

Up Next

Continue with Packages — working with npm packages.