How do you import a module in Node.js?

 In Node.js, you can import modules using either the CommonJS syntax or the ES Module (ESM) syntax, depending on your project setup.

✅ 1. CommonJS (Default in Node.js)

Most Node.js projects use CommonJS by default.

// Importing a built-in module
const fs = require('fs');

// Importing a third-party module
const express = require('express');

// Importing your own module
const myModule = require('./myModule');

• Works out of the box in .js files.

• Used widely in older Node.js codebases.

✅ 2. ES Modules (ECMAScript Modules)

If your project uses "type": "module" in package.json or your file has a .mjs extension, you can use ESM syntax:

js

// Importing a built-in or third-party module
import fs from 'fs';
import express from 'express';

// Importing your own module
import myModule from './myModule.js';


⚠️ Note: Relative imports in ESM must include the file extension (.js, .mjs, etc.).

When to Use Which?

Project Type	Use
Traditional Node.js	require()
Modern, ESM-based	import
Bundled front-end apps	import (via tools like Webpack, Vite)