Knowing how to use the --save option when installing Node.js using npm

Getting to Know npm install --save

When working with Node.js, you may encounter the npm install --save command in numerous tutorials and manuals. This option was historically significant for managing project dependencies. Understanding its purpose and usage is critical for successful Node.js development.

This page explains the --save option, its significance in package management, and its evolution over time. Whether you're a newbie or an experienced developer, understanding the nuances of npm commands can help you manage and publish your projects more effectively.

Exploring npm install --save and modern alternatives

The scripts in the examples above show how to start a Node.js project and configure a simple server with Express.js. The first script demonstrates the historical use of the npm install --save command. Initially, developers used npm init -y to generate a new Node.js project with default parameters. This command creates a package.json file, which is essential for maintaining project dependencies. The npm install express --save command installed the Express.js package and added it explicitly to the dependencies portion of the package.json file. This allowed anyone cloning the project to run npm install and install all required dependencies.

The script imports the Express.js module with const express = require('express');, creates an Express application instance with const app = express();, and defines a simple route handler for GET requests to the root URL. The server listens on a specific port, as indicated by app.listen(port, callback);. The second script demonstrates the contemporary technique, in which the --save option is no longer required. Running npm install express automatically changes the dependencies section in package.json, making the process easier. The remainder of the script stays unaltered, illustrating that the fundamental functionality of configuring and running an Express.js server is consistent regardless of installation method.

// Step 1: Initialize a new Node.js project
npm init -y
// Step 2: Install a package with the --save option (deprecated)
npm install express --save
// Step 3: Create a simple server using Express
const express = require('express');
const app = express();
const port = 3000;
app.get('/', (req, res) => {
  res.send('Hello World!');
});
app.listen(port, () => {
  console.log(`Server is running on port ${port}`);
});

// Step 1: Initialize a new Node.js project
npm init -y
// Step 2: Install a package without the --save option
npm install express
// Step 3: Create a simple server using Express
const express = require('express');
const app = express();
const port = 3000;
app.get('/', (req, res) => {
  res.send('Hello World!');
});
app.listen(port, () => {
  console.log(`Server is running on port ${port}`);
});

The Evolution of npm Dependency Management.

Previously, handling dependencies in Node.js projects relied heavily on the --save option in npm install. When developers run the npm install --save command, npm will add the installed package to the dependencies portion of the package.json file. This made it apparent which packages were required for the application to function in production. Without this option, the installed packages were not recorded in the package.json, making it difficult to share the project with others or maintain consistency across different installations.

However, after npm version 5, the --save option is no longer required. By default, npm install adds the installed package to the dependencies section in package.json. This update makes the process of handling dependencies easier and more intuitive. In addition, npm provides other sections in package.json for different types of dependencies, such as devDependencies for packages needed only during development, peerDependencies for packages that work alongside others, and optionalDependencies for packages that are not essential but improve functionality if available.