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

Named exports use the `export` keyword with curly braces wrapping the identifier, or are placed directly before the declaration.

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

A TypeScript/ES module can have at most one `export default`, while it may have any number of named exports.

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

`import type` guarantees the import is type-only and is completely removed during compilation, ensuring it never appears in the emitted JavaScript.

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 barrel file (typically `index.ts`) consolidates re-exports from several modules in a directory, letting consumers import from one path instead of many.

Question 5

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

Accepted Answer

moduleResolution

Answer

The `moduleResolution` option determines the module resolution strategy TypeScript uses (e.g., `node`, `bundler`, `node16`, `nodenext`).

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TypeScript TypeScript Functions & Modules 2