Advanced Patterns — Series 3

Preview — 3 of 10 questions

What is the output of the following code?

javascript

const config = { server: { port: 8080 } };
const { server: { host = 'localhost', port } = {}, timeout = 30 } = config;

console.log(host, port, timeout);

Aundefined 8080 30

Blocalhost undefined 30

Clocalhost 8080 30

DTypeError: Cannot destructure property 'host' of undefined

What will the following code log?

javascript

function make() {
  let value = 'first';
  const read = () => value;
  value = 'second';
  return read;
}

console.log(make()());

Asecond

Bfirst

Cundefined

DReferenceError: value is not defined

What is logged?

javascript

const user = { id: 1, name: 'Ada', meta: { active: true } };
const { id, ...rest } = user;

rest.meta.active = false;

console.log(id, 'id' in rest, user.meta.active);

A1 true false

B1 true true

C1 false true

D1 false false

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