Standard Library — Chapter Quiz

Question 1

1

Which is the modern promise-based fs import?

Aimport fs from "node:fs"Bimport * as fs from "node:fs/promises"Crequire("fs/async")Dimport promises from "node:fs"

node:fs/promises is the promise-based namespace — modern default.

Question 2

2

readFileSync is safe to use inside an HTTP request handler.

TTrueFFalse

Sync IO blocks the event loop — every other request waits. Use async fs in handlers; sync only at startup or in scripts.

Question 3

3

Why prefer path.join('a','b') over 'a/' + 'b'?

AIt is fasterBCross-platform separator handling and avoids double slashesCIt returns a PromiseDNo real difference

path.join uses the correct separator per OS and normalizes slashes — your code works on macOS, Linux, AND Windows.

Question 4

4

What is EventEmitter's once(name, fn) for?

ARegister a listener that fires foreverBRegister a listener that fires once, then auto-removesCRemove a listenerDMake a listener immutable

once runs the listener the next time the event fires, then removes it automatically.

Question 5

5

Why use streams instead of readFile for big files?

AStreams are easier to readBStreams process data in chunks with constant memoryCStreams are faster on small filesDreadFile is deprecated

Streams process chunks as they arrive — constant memory regardless of file size. readFile loads everything at once.

Question 6

6

The global object that exposes args, env, pid, and signals is called ___.

process is the global handle to the running Node process.

Question 7

7

What is the secure way to generate a random session token?

AMath.random().toString(36)BDate.now().toString(16)Ccrypto.randomBytes(16).toString("hex")Dbtoa("salt" + userId)

crypto.randomBytes is cryptographically secure. Never use Math.random() for security-sensitive values.

Question 8

8

Which streams ship in node:stream?

Select all that apply.

Readable, Writable, Transform (R+W), and Duplex are the four stream types. "Async" is not a stream type.

Test what you learned.