Flash cards
Review the key moves
What is the main idea behind Node.js NPM?
Lesson checks
Practice each idea before moving on
Short Mimo-style checks built from this lesson's code, terms, and sequence.
Which statement best captures the main point of this lesson?
Complete the missing token from the example code.
___ uc = require('upper-case');Put the learning moves in the order that makes the concept easiest to apply.
What is NPM?
NPM is a package manager for Node.js packages, or modules if you like.
www.npmjs.com hosts thousands of free packages to download and use.
The NPM program is installed on your computer when you install Node.js
If you installed Node.js, NPM is already ready to run on your computer!
What is a Package?
A package in Node.js contains all the files you need for a module.
Modules are JavaScript libraries you can include in your project.
Using a Package
Once the package is installed, it is ready to use.
Include the "upper-case" package the same way you include any other module:
let uc = require('upper-case');Create a Node.js file that will convert the output "Hello World!" into upper-case letters:
Example
let http = require('http');
let uc = require('upper-case');
http.createServer(function (req, res) {
res.writeHead(200, {'Content-Type': 'text/html'});
res.write(uc.upperCase("Hello World!"));
res.end();
}).listen(8080);Save the code above in a file called "demo_uppercase.js", and initiate the file:
Initiate demo_uppercase:
C:\Users\
Your Name
>node demo_uppercase.jsIf you have followed the same steps on your computer, you will see the same result as the example: [http://localhost:8080
Global Packages
Packages can be installed globally, making them available as command-line tools anywhere on your system.
Global packages are typically used for CLI tools and utilities.
Install a package globally
npm install -g package-nameExample: Install the http-server package globally
npm install -g http-serverAfter installation, you can run the package from any directory:
http-serverNote
On some systems, you might need administrator/root privileges to install packages globally.
On Unix-like systems, use sudo before the command.
Updating Packages
To keep your packages up to date, you can update them using the following commands:
Update a specific package
npm update package-nameUpdate all packages in your project
npm updateCheck for outdated packages
npm outdatedTip
To update npm itself, run: npm install -g npm@latest
Uninstalling a Package
To remove a package that you no longer need, you can use the uninstall command:
Remove a package
npm uninstall package-nameRemove a global package
npm uninstall -g package-nameRemove a package and its dependencies
npm uninstall --save package-nameNote
The --save flag updates your package.json file to remove the dependency.
For older versions of npm, you might need to use --save-dev for development dependencies.