Node.js

Node.js is a JavaScript runtime used to execute code without a web browser. The node environment lets developers create web apps, servers, scripts and command line tools.

Working with module export

File: math.js

const add = (x, y) => x + y;
const multiply = (x, y) => x * y;
const PI = 3.14;
 
exports.add = add;
exports.multiply = multiply;
exports.PI = PI;

File: app.js

// requiring a script
const { PI, multiply } = require("./math");
 
console.log(PI);
 
// requiring a folder is the same, but need an index.js file inside it
// requiring a package just use the package name as argument

NPM

The NPM (Node Package Manager) is the standard package manager for Node.js.

# initialize a node package
npm init
 
# install package
npm i <package_name>
 
# install dependencies from package.json file
npm i