Handling Modules in Node.js

Topic Outline (30-min)

1. Importing and Exporting Modules:

   • Node.js modules are reusable JavaScript files that can be imported or exported.

   • CommonJS Syntax:

     • Export:

       javascript코드 복사// factorial.js
       const factorial = (n) => (n <= 1 ? 1 : n * factorial(n - 1));
       module.exports = factorial;

     • Import:

       javascript코드 복사const factorial = require('./factorial');
       console.log(factorial(5)); // Output: 120

   • ES6 Syntax:

     • Export:

       javascript코드 복사export const factorial = (n) => (n <= 1 ? 1 : n * factorial(n - 1));

     • Import:

       javascript코드 복사import { factorial } from './factorial.js';
       console.log(factorial(5)); // Output: 120

2. Core vs. Third-Party Modules:

   • Core Modules: Built into Node.js (e.g., fs, http, path).

   • Third-Party Modules: Installed using npm (e.g., chalk, express).

3. Introduction to npm for Package Management:

   • Install npm packages:

     bash코드 복사npm install <package-name>

   • Global vs. local installation:

     • Local: Installs package in the project directory (node_modules).

     • Global: Installs package system-wide.

     bash코드 복사npm install -g <package-name>

4. Working with package.json and Dependency Management:

   • Initialize a project with package.json:

     bash코드 복사npm init -y

   • Add dependencies:

     bash코드 복사npm install chalk

   • Use scripts in package.json:

     json코드 복사{
       "scripts": {
         "start": "node app.js"
       }
     }