What is npm?

What is npm?

npm, short for Node Package Manager, is the default package manager for Node.js. It acts as a tool that allows developers to install, share, and manage code packages written in JavaScript. Whether you're building a backend server or a frontend project, npm makes it easier to include and maintain third-party libraries in your application.

Why Do Developers Use npm?

As applications grow in complexity, reusing code and managing dependencies becomes essential. Instead of writing everything from scratch, npm provides access to a massive collection of reusable packages. Developers use it to:

• Install open-source libraries
• Track and manage project dependencies
• Automate repetitive tasks using npm scripts
• Maintain consistency across development environments

Installing npm

npm comes bundled with Node.js, so when you install Node.js from the official website, npm is installed automatically.

# To check if npm is installed
npm -v

# To check Node.js version
node -v
  

Initializing a Project with npm

To start a new Node.js project, you can create a package.json file using the npm init command. This file keeps track of the project's dependencies, scripts, version, and other metadata.

# Start project setup interactively
npm init

# Or quickly create a default package.json file
npm init -y
  

Installing Packages with npm

You can easily install external packages using npm. Installed packages will be added to the node_modules directory and listed in package.json under dependencies.

# Install a package (e.g., express)
npm install express

# Install a package globally
npm install -g nodemon
  

Understanding Dependencies and devDependencies

Packages required to run the application go under dependencies. Packages used only during development (like testing tools) are listed as devDependencies.

# Install a dev dependency
npm install jest --save-dev
  

Running Scripts with npm

The scripts section in package.json allows you to define commands that can be executed using npm run. This is commonly used for building, testing, and starting your app.

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

# Run the start script
npm start

# Run the test script
npm test
  

Accessing the npm Registry

npm fetches packages from the npm registry — a massive online repository of public packages. You can also publish your own packages to the registry using the npm publish command.

Uninstalling Packages

If you no longer need a package, you can easily remove it using the uninstall command.

npm uninstall express
  

Conclusion

npm is a vital tool in the JavaScript and Node.js ecosystem. It simplifies package management, improves development workflows, and makes it easier to collaborate on projects. Whether you're building a personal tool or an enterprise application, understanding how to use npm effectively is an essential skill for any JavaScript developer.