ES6 Modules
Modules let you split code into separate files. Use export to expose values and import to consume them.
// math.js
export const PI = 3.14159;
export function add(a, b) { return a + b; }
// main.js
import { PI, add } from "./math.js";
console.log(PI);
console.log(add(2, 3));Default Exports
Each module can have one default export. Import it without curly braces — you can name it anything.
// greeter.js
export default function greet(name) {
return "Hello, " + name;
}
// main.js
import greet from "./greeter.js";
console.log(greet("Alice"));
// You can also export a class as default
// export default class User { ... }Named vs Default Imports
Mix named and default imports in one statement. Use * as to import everything as a namespace.
// utils.js
export const VERSION = "1.0";
export function log(msg) { console.log("[LOG]", msg); }
export default function error(msg) { console.error("[ERROR]", msg); }
// main.js
import error, { VERSION, log } from "./utils.js";
log("App version " + VERSION);
error("Something broke");
// Or import all
import * as utils from "./utils.js";
console.log(utils.VERSION);