Modules

JavaScript modules allow you to break up your code into separate files.

This makes it easier to maintain the code-base.

ES Modules rely on the import and export statements.

Export

You can export a function or variable from any file.

Let us create a file named person.js, and fill it with the things we want to export.

There are two types of exports: Named and Default.

Named Exports

You can create named exports two ways. In-line individually, or all at once at the bottom.

export const name = "Jesse"
export const age = 40

const name = "Jesse"
const age = 40

export { name, age }

Default Exports

Let us create another file, named message.js, and use it for demonstrating default export.

You can only have one default export in a file.

const message = () => {
  const name = "Jesse";
  const age = 40;
  return name + ' is ' + age + 'years old.';
};

export default message;

Import

You can import modules into a file in two ways, based on if they are named exports or default exports.

Named exports must be destructured using curly braces. Default exports do not.

import { name, age } from "./person.js";

import message from "./message.js";