JavaScript Modules 2

Question 1

What does `export default` allow you to do differently than named exports?

Accepted Answer

Export a single value without specifying a name on import

Answer

`export default` lets the importing module choose any name for the imported value, since there's only one default per module.

Question 2

Which syntax correctly re-exports a named export `helper` from `./utils.js`?

Accepted Answer

export { helper } from './utils.js';

Answer

The `export { name } from 'module'` syntax re-exports without importing into the current scope.

Question 3

What happens if you use `import` at the top of a script tag without `type="module"`?

Accepted Answer

A SyntaxError is thrown because import is only valid in module context

Answer

The `import` declaration is only valid inside ES modules; using it in a classic script causes a SyntaxError.

Question 4

What is the value of `import.meta.url` inside an ES module?

Accepted Answer

The URL of the current module file

Answer

`import.meta.url` resolves to the absolute URL of the specific module file in which it appears.

Question 5

How can you import all named exports from a module into a single namespace object?

Accepted Answer

import * as ns from './mod.js';

Answer

The `import * as ns` syntax creates a module namespace object containing all named exports.

JavaScript Practice Test