Javascript Modules

Javascript modules encapsulate code so it can be extended and reused.

import * as fs from node:fs

export default function getFiles() {
  let files = fs.readdirSync('images')
}

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

There are several different module standards.

Native JS modules use import and export. The .mjs extension is recommended.

Common JS uses require and module.exports. It uses the .cjs extension.

Package.json

Package definition for NPM.

Created by npm init.

npm install installs dependencies from package.json into node_modules and updates package-lock.json, which keeps track of the installed versions. (If not adding a new module, dependency versions are read from package-lock.json.

Use type: "module" to declare the package as a JS module. This will use es module syntax in .js files.

https://docs.npmjs.com/cli/v10/configuring-npm/package-json

Import

import { open } from "sqlite"
import sqlite3 from "sqlite3"

When should you use the brackets around imported modules?

importmap

https://developer.mozilla.org/en-US/docs/Web/HTML/Element/script/type/i…