Browser APIs & Storage — Series 3

Preview — 3 of 10 questions

What is logged?

javascript

localStorage.setItem('count', 5);
localStorage.setItem('flag', false);

console.log(
  typeof localStorage.getItem('count'),
  localStorage.getItem('count') + 1,
  localStorage.getItem('flag') === false,
  Boolean(localStorage.getItem('flag')),
);

Anumber 6 true false

Bstring 51 false true

Cstring 6 false false

Dnumber 6 false true

Which statement is correct?

AAll three are sent to the server on every request; only their expiry differs.

BsessionStorage is shared across all tabs of the same origin; localStorage is per-tab.

ClocalStorage expires when the browser closes; sessionStorage persists indefinitely.

DlocalStorage persists until it is cleared and is shared across tabs of the origin; sessionStorage is scoped to one tab and cleared when it closes; cookies are the only one automatically sent with requests.

What is logged?

javascript

console.log(localStorage.getItem('missing'), JSON.parse(localStorage.getItem('missing')));

try {
  JSON.parse(undefined);
} catch (e) {
  console.log(e.constructor.name);
}

Anull null then SyntaxError

Bundefined undefined then TypeError

Cnull then SyntaxError then SyntaxError

Dnull null then nothing — JSON.parse(undefined) returns undefined

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