Difference Between Node Require and ES6 Import And Export

Importing modules makes your code reusable. NodeJS offers two ways to do this: CommonJS (require()) and ES6 modules (import/export). Both achieve the same goal—sharing code, but use different syntax.

CommonJS is the older, traditional way. ES6 modules are newer and offer some advantages, but both are commonly used in NodeJS development.

Node Require v/s ES6 Import And Export

Here's a comparison between NodeJS's require and ES6's import/export syntax:

In Node.js, require() and ES6 import/export each have their own use cases, so choose the one that best suits your requirements.

Node's require (CommonJS)

The require function is part of the CommonJS module system, which NodeJS uses to handle modules. It allows you to include external modules, JSON files, or local files in your application.

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

// Importing a local module
const myModule = require('./myModule');

// Exporting a function
module.exports = function() {
 console.log('Hello from myModule!');
};

• require('fs'): Imports the built-in file system module.
• require('./myModule'): Imports a local module named myModule.
• module.exports: Exports a function from the current module.

Key Features of require()

• Synchronous: Modules are loaded synchronously, which means the execution waits for the required module to be fully loaded before continuing.
• Single Export Object: A module can export multiple properties, but they are grouped into a single object.
• Dynamic Loading: require() can be used anywhere in the code, meaning modules can be conditionally loaded.
• CommonJS Standard: It's specific to NodeJS and not native to browsers.

Why Use NodeJS require()?

While ES6 modules are gaining popularity, require() (CommonJS) is still widely used in NodeJS, especially in older projects and libraries. It's important to understand how it works.

• It's the traditional and default way to import modules in many NodeJS projects.
• It's simple and has a straightforward syntax.
• Many existing npm packages and code examples use require().

ES6 Import & Export

ES6 introduced a standardized module system with import and export statements, offering a more declarative and flexible approach to module handling. This system supports both static and dynamic imports.

// Importing a built-in module
import fs from 'fs';

// Importing a local module
import { myFunction } from './myModule';

// Exporting a function
export function myFunction() {
 console.log('Hello from myFunction!');
}

• import fs from 'fs': Imports the default export from the built-in file system module.
• import { myFunction } from './myModule': Imports a named export myFunction from a local module.
• export function myFunction(): Exports a function named myFunction from the current module.

Key Features of import/export

• Static Imports: Modules are loaded at the top of the file, making them statically analyzable, and cannot be conditionally loaded (though dynamic imports can be done with import()).
• Named and Default Exports: A module can export multiple values, and they can be imported individually by name.
• Asynchronous: ES6 modules are asynchronous by default, meaning they are loaded non-blockingly.
• Native to JavaScript: This module system is a standard in modern JavaScript and works in both NodeJS and browser environments.

Why Use ES6 import and export?

ES6 modules (import/export) offer a modern and often preferred way to handle modules in JavaScript, including NodeJS. They bring several advantages.

• They offer a cleaner and more declarative syntax compared to require().
• They support asynchronous module loading, potentially improving performance.  
• They enable static analysis, which can help catch errors during development.  
• They are the standard for browser-based JavaScript modules, promoting consistency across environments.

Conclusion

Both require and import/export are used to load modules in NodeJS, but they differ in their module systems, loading mechanisms, and syntax. While require is synchronous and based on CommonJS, ES6 import/export offers asynchronous, statically-analyzable imports, making it more suitable for modern JavaScript development.