Node.js NPM
NPM is a package manager for Node.js packages, or modules.
NPM is used to download and install Node.js packages, or modules into your system.
NPM helps install, manage, and share JavaScript libraries and tools.
1.Initializing a New Project
mkdir node-website
cd node-website
npm init
It will ask for details like name, version, description, etc. You can skip all by running:
npm init -y
This creates a package.json file.
2. Installing Packages
npm install express
OR
npm i express
3. Install a package globally
npm install -g nodemon
Global packages are installed system-wide and can be used from any project.
4. Uninstalling Packages
npm uninstall express
npm uninstall -g nodemon
5. View installed packages
npm list
6. View outdated packages
npm outdated
7. Update all packages
npm update
8. Install dependencies from package.json
npm install
9. Running Scripts with NPM
Inside package.json, add: json
"scripts": {
"start": "node server.js",
"dev": "nodemon server.js"
}
Run the script:
npm run start npm run dev
Below NPM command is used to install express package.
D:\nodejs\node-website> npm install express
Below NPM command is used to install moment package.
D:\nodejs\node-website> npm install moment
Below NPM command is used to install path package.
D:\nodejs\node-website> npm install path
Below NPM command is used to install async package.
D:\nodejs\node-website> npm install async
Below NPM command is used to install mysql package.
D:\nodejs\node-website> npm install mysql
Example for express package:
const express = require('express');
const app = express();
app.get('/', (req, res) => {
res.send('Hello, World!');
});
app.get('/aboutus', (req, res) => {
res.send('About us!');
});
app.listen(3000, () => {
console.log('Server running on http://localhost:3000');
});
Example for moment package :
const moment = require('moment');
// Get current date and time
console.log("Current Date & Time:", moment().format('YYYY-MM-DD HH:mm:ss'));
// Format a date
const myDate = moment('2025-02-18');
console.log("Formatted Date:", myDate.format('MMMM Do YYYY, h:mm:ss a'));
// Add days to the current date
console.log("Date after 5 days:", moment().add(5, 'days').format('YYYY-MM-DD'));
// Subtract months from the current date
console.log("Date 2 months ago:", moment().subtract(2, 'months').format('YYYY-MM-DD'));
// Get the day of the week
console.log("Day of the week:", moment().format('dddd'));
// Get time from now
console.log("Time from now:", moment("2024-12-31").fromNow());
// Check if a date is valid
console.log("Is the date valid?", moment("2024-02-30").isValid());
Output :
Current Date & Time: 2025-02-17 13:00:47
Formatted Date: February 17th 2025, 12:00:00 am
Date after 5 days: 2025-02-23
Date 2 months ago: 2024-12-18
Day of the week: Tuesday
Time from now: 2 months ago
Is the date valid? false
Example for path package:
const path = require('path');
// Get file path dynamically
const filePath = path.join(__dirname, 'data', 'example.txt');
console.log("Current Directory:", __dirname);
console.log("File Path:", filePath);
console.log("File Extension:", path.extname(filePath));
console.log("File Name:", path.basename(filePath));
console.log("Directory Name:", path.dirname(filePath));
Output :
Current Directory: D:\xampp\htdocs\nodejs_tuttorials
File Path: D:\xampp\htdocs\nodejs_tuttorials\data\example.txt
File Extension: .txt
File Name: example.txt
Directory Name: D:\xampp\htdocs\nodejs_tuttorials\data
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