Difference Between Node require and ES6 Import and Export

When working with JavaScript, especially in a Node.js or modern JavaScript environment, you often come across two popular module systems: use require which comes from the CommonJS and import and export keywords which came with ES6. They are both used with the same goal of modularizing your code but they differ as to how and what you use or do with them. Now let us discuss these differences in a greater detail.

What is Node.js require?

The require is the module-loading mechanism in CommonJS, the default module system for Node.js. It allows you to include modules, JSON files, or local files into your application.

Example of require:

const fs = require('fs');
const myModule = require('./myModule');

• Synchronous Loading: This is a characteristic of modules they are loaded synchronously, this means the program waits for the module to be loaded before the next line of code is executed.
• File Extension Flexibility: You can skip the file extension while requiring.js files as Node automatically appends.js at the end.
• Dynamic Loading: This brings the good news that all the modules can be conditionally loaded at runtime so that only those parts that are still relevant and useful can be loaded by the system.

Advantages:

• All is smooth out of the box with Node.js.
• Free-form and supported almost anywhere.

Limitations:

• Synchronous, which could not be very suitable for some circumstances.
• Does not work independently in browsers especially in those with no tools such as Browserify.

What is ES6 import and export?

ES6 modules are a standard way of doing modular JavaScript. They have a clean syntax and more features than CommonJS as compared to the later.

Example of import/export:

Module: myModule.js

export const greet = () => {
  console.log('Hello, world!');
};

export default function () {
  console.log('Default export function');
}

Main File:

import greetFunction, { greet } from './myModule.js';

greet(); // Hello, world!
greetFunction(); // Default export function

• Asynchronous Loading: ES6 modules are loaded asynchronously which makes them better for asynchronous loading.
• Static Structure: Where import/export is concerned, it is statically analyzed so that it can be made more hopeful and easier to forecast.
• Named and Default Exports: It works with multiple named export and it also supports one default export only.

Advantages:

• Is compatible with the newest versions of browsers and offers tree-shaking as one of its opportunities.
• Eliminates messy and repetitive code and an enhancement of code constructing vocabulary or declarative statements.

Limitations:

• Requires a transpiler like Babel or support from Node.js for older versions.
• The .mjs extension is needed for ES6 modules in Node.js unless type: "module" is specified in package.json.

Key Differences

The following table highlights major differences between Node.js require and ES6 import, export ?

When to Use Which?

• Often while writing Node.js code when dealing with old codes in Node.js.
• If you have a situation where certain modules have to be loaded after runtime.

Use ES6 import/export

• When building modern JavaScript applications.
• For projects that need browser compatibility and tree-shaking.

Migrating from require to import/export

1. Do not use module.exports instead use either export default or export {}.
2. Swapping out require() statements with import statements.
3. Ensure your project is configured for ES6 modules (type: "module" in package.json).

Example

// Old CommonJS
const math = require('./math');
math.add(2, 3);

// New ES6 Module
import { add } from './math.js';
add(2, 3);

Conclusion

They both are effective to handle the dependencies and to break the system into modules and all of them are inbuilt within Go. Though, require is a older standard used in node.js, it has been replaced by import/export statements which is better in all sense such as syntactically, performance wise, and supports browsers better.

Therefore, comparing these differences, you will be in a position to judge which among the two suits your project requirements.