TypeScript TypeScript Functions & Modules 2

Question 1

Which of the following correctly creates a named export in a TypeScript ES module?

Accepted Answer

export { myFunc };

Answer

module.exports = { myFunc };

Answer

exports.myFunc = myFunc;

Answer

export default myFunc;

Question 2

How many `export default` statements can a single TypeScript module have?

Accepted Answer

Exactly one — a module may have only one default export

Answer

Unlimited — one per exported value

Answer

Up to two — one for a type and one for a value

Answer

Zero — default exports are not allowed in TypeScript

Question 3

What does `import type { Foo } from './foo'` do differently than `import { Foo } from './foo'`?

Accepted Answer

It imports only the type information, which is fully erased in the compiled JavaScript

Answer

It imports the value and the type together for runtime use

Answer

It imports Foo as a module namespace object

Answer

It makes the import lazy and returns a Promise

Question 4

What is a 'barrel file' in TypeScript module organization?

Accepted Answer

An `index.ts` file that re-exports from multiple sibling modules as a single entry point

Answer

A file that compresses all module imports into a single bundle

Answer

A file containing only ambient type declarations

Answer

A configuration file that maps module paths to file locations

Question 5

Which `tsconfig.json` compiler option controls how TypeScript locates module files?

Accepted Answer

moduleResolution

Answer

moduleType

Answer

resolveModules

Answer

importResolution

Question 6

What does `export * from './module'` accomplish in TypeScript?

Accepted Answer

Re-exports all named exports from the module, excluding the default export

Answer

Re-exports only the default export of the module under a new name

Answer

Imports the entire module namespace and merges it with the current module's namespace

Answer

Creates type aliases for every export in the specified module

Question 7

What is the primary purpose of `declare module` in a TypeScript `.d.ts` file?

Accepted Answer

To provide type information for external JavaScript modules that lack their own type definitions

Answer

To create a runtime module wrapper around existing code

Answer

To declare a private module namespace scoped to a single file

Answer

To configure how CommonJS modules are imported