How do ES modules (import/export) work in JavaScript?

Each file is its own module: export exposes values from it and import pulls them into another file.

Exporting (hello.js):

const value = { text: 'hello world' };
export default value;

Importing (main.js):

import hello from './hello.js';
// 'hello world'
console.log(hello.text);

Key concepts:

• Each file is a module with its own scope
• export default exports one main value
• import name from './file.js' imports the default export
• The imported name can be anything you choose

Named exports (alternative):

// math.js
export const add = (a, b) => a + b;
export const subtract = (a, b) => a - b;

// main.js
import { add, subtract } from './math.js';