Node Package Manager(npm)

The npm package is the standard package manager for Node.js. This package is also used in the frontend to manage project dependencies.

How do we use npm?

First, we initialize the project and create a basic package.json file, like this:

npm init

If a package.json file already exists, we can install all the project dependencies by running this code:

npm install

To install a single package, we use the following code:

npm install <package_name>

To install a single package globally, we use the following code:

npm install <package_name> -g

To update installed packages, we use the following code:

npm update

To update a single installed package, we use the following code:

npm update

To run a task, we use the following code:

npm run <task_name>

The package.json file

The package.json file is created by the npm package when initializing a project. We can think of the package.json file as a project manifest that contains all the project settings. It’s where we can store names and different versions of all the installed packages.

Here’s a typical package.json file generated by the npm package:

{
  "name": "Educative Nodejs Full-Stack Course",
  "version": "0.1.0",
  "description": "A full-stack application built using React, Nodejs, Express, and MongoDB",
  "main": "index.js",
  "scripts": {
    "start": "node index.js"
  },
  "dependencies": {
    "express": "^14.0.0"
  },
  "repository": {
    "type": "git",
    "url": "https://github.com/aashrafh/educative-Nodejs-fullstack-course"
  },
  "keywords": [
    "node",
    "express"
  ],
  "author": "Ahmed Ashraf",
  "contributors": [
    "Ahmed Ashraf <ahmed.ashraf.cmp@gmail.com> (https://github.com/aashrafh)"
  ],
  "license": "MIT"
}

The package.json file is a typical JSON object that has a set of key-value pairs. Each property below indicates an important part of the project setting that’s used by the npm package or other tools:

• The version indicates the current version of the project.

• The description consists of a few words about the application.

• The main property sets the entry point of the project.

• The scripts are a set of node scripts that we can run.

• The dependencies set a list of all the installed npm packages.

• The repository is the location of the application or package.

• The keywords array describes what our application 0r package does.

• The author property is the name of the author.

• The contributors array lists all the contributors.

• This license property is the license of the application or package.

The packages-lock.json file

The packages-lock.json file is automatically generated by the npm package, and we, most probably, won’t need to edit or modify it. This file is used to track the exact version of each installed package so that the application can be reproduced with 100% accuracy, even if the package is updated by its maintainer.