ES Modules import and export in Node.js - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the main purpose of ES Modules in Node.js?

ES Modules allow you to organize and reuse code by importing and exporting functions, objects, or values between files in a clear and standardized way.

beginner

How do you export a single function as the default export in an ES Module?

Use export default functionName; to export a single function as the default export from a module.

beginner

What is the syntax to import a default export from another module?

Use <code>import anyName from './module.js';</code> where <code>anyName</code> is your chosen name for the default export.

intermediate

How do you export multiple named values from a module?

Use <code>export const name1 = value1;</code> or <code>export { name1, name2 };</code> to export multiple named values.

intermediate

How can you import multiple named exports from a module?

Use <code>import { name1, name2 } from './module.js';</code> to import specific named exports.

Which keyword is used to export a default value in ES Modules?

A require

B export const

C module.exports

D export default

The export default keyword exports a single default value from a module.

How do you import a named export called calculate from a module?

A import { calculate } from './module.js';

B import calculate from './module.js';

C const calculate = require('./module.js');

D export { calculate } from './module.js';

Named exports are imported using curly braces: import { calculate } from './module.js';.

What file extension should you use for ES Modules in Node.js by default?

A .mjs

B .cjs

C .js

D .json

The .mjs extension explicitly marks a file as an ES Module in Node.js.

Which statement is true about mixing CommonJS and ES Modules in Node.js?

A You can freely mix <code>require</code> and <code>import</code> in the same file.

B ES Modules can import CommonJS modules, but CommonJS cannot import ES Modules directly.

C CommonJS modules are the same as ES Modules.

D You must rename all files to .cjs to use ES Modules.

ES Modules can import CommonJS modules, but CommonJS modules cannot directly import ES Modules without special handling.

How do you export a variable named count as a named export?

A export default count;

B import count from './module.js';

C export { count };

D module.exports = count;

Use export { count }; to export count as a named export.

Explain how to export and import both default and named values using ES Modules in Node.js.

Think about how you share one main thing versus multiple things from a file.

Describe the difference between ES Modules and CommonJS modules in Node.js and how they interact.

Consider the keywords and compatibility between the two module systems.