Introduction to NPM (Node Package Manager)

What is a Package Manager?

A package manager is a tool that helps manage software dependencies. It simplifies the process of installing, updating, configuring, and removing software packages.

What is npm?

npm stands for Node Package Manager. It is the default package manager for Node.js. npm enables developers to install, share, and distribute code as well as reuse existing solutions for common tasks.

Installing npm (and Node.js)

To get started with npm, you need to first install Node.js, which includes npm by default. You can download it from the official website:

# For Windows or macOS
https://nodejs.org/en/download/

# For Linux
sudo apt-get install nodejs

After installation, you can verify the installation by running:

node -v
npm -v

This will print out the installed versions of Node.js and npm.

Configuring npm

You can configure npm using the npm config command. For example, to set a custom registry:

npm config set registry https://registry.npmjs.org/

Updating npm

To update npm to the latest version, use the following command:

npm install -g npm

Uninstalling npm

Since npm comes bundled with Node.js, uninstalling npm typically involves uninstalling Node.js. On Windows or macOS, you can simply remove the Node.js application. On Linux, you can use:

sudo apt-get remove nodejs

Where can I find npm documentation?

The npm documentation is available online at:

https://docs.npmjs.com/

Searching the npm Registry

To search for a package in the npm registry, use:

npm search <package-name>

For example:

npm search express

This will list all packages related to “express”.

Installing and Updating Packages from the npm Registry

Installing Packages Locally

To install a package locally (for your project):

npm install express

This creates a node_modules directory in your project and installs the express package there.

Installing Packages Globally

To install a package globally (available system-wide):

npm install -g express

Updating Packages

To update a local package:

npm update express

To update all packages:

npm update

Listing npm Packages

To list all installed packages locally:

npm list

To list all global packages:

npm list -g --depth=0

Uninstalling npm Packages

To uninstall a local package:

npm uninstall express

To uninstall a global package:

npm uninstall -g express

package.json File

The package.json file is a configuration file for your project. It stores metadata about your project and its dependencies.

Package Details are Stored in package.json

Example package.json:

{
  "name": "my-app",
  "version": "1.0.0",
  "dependencies": {
    "express": "^4.17.1"
  }
}

Viewing package.json Before Installing

You can view the package.json file before installing dependencies:

cat package.json

Interactively Create a package.json File

To create a package.json file interactively:

npm init

This will guide you through creating a package.json file step-by-step.

NPM is Great, But I am a Front-End Engineer and NPM is for Backend JS Developers

While NPM is commonly used for backend development, it’s also widely used in front-end projects. Many front-end libraries and tools (e.g., React, Vue, Webpack) have their own npm packages. Using npm can streamline your workflow and help manage dependencies effectively.

This introduction covers the basics of npm and how to use it effectively in both front-end and back-end projects.