Splitting Code Into Parts

As a project grows, keeping everything in one file becomes unmanageable. ES Modules let you split your code into logical, reusable pieces.

export — Share Your Code

// math.js
export function add(a, b) { return a + b; }
export function multiply(a, b) { return a * b; }
export const PI = 3.14159;

// Export everything at once:
export { add, multiply, PI };

import — Use Others' Code

// main.js
import { add, PI } from './math.js';
console.log(add(2, 3)); // 5
console.log(PI);         // 3.14159

// Import everything under a namespace:
import * as Math from './math.js';
console.log(Math.multiply(4, 5)); // 20

Using Modules in the Browser

<script type="module" src="main.js"></script>