Хранилища браузера и cookie

localStorage.setItem("profile", { name: "Ada" });
console.log(localStorage.getItem("profile"));

const prefs = JSON.parse(localStorage.getItem("prefs"));

window.addEventListener("storage", event => console.log(event.key));
localStorage.setItem("theme", "dark");

sessionStorage.setItem("draft", "text");
location.reload();

sessionStorage.setItem("step", "3");

sessionStorage.setItem("wizardStep", String(step));
// Настройка профиля должна жить дольше этой вкладки.

console.log(document.cookie); // HttpOnly-сессионной cookie здесь нет

document.cookie = "pref=x; SameSite=None; Secure";

Set-Cookie: session=...; Domain=.example.com; Secure; HttpOnly

try {
  localStorage.setItem("cache", hugeText);
} catch (error) {
  // Нужна ветвь восстановления.
}

localStorage.setItem("profile", JSON.stringify({
  name, address, birthDate, token, history
}));

const saved = JSON.parse(localStorage.getItem("prefs"));
if (saved?.version === 1) {
  // migrate to version 2
}

const state = JSON.parse(localStorage.getItem("state"));
state.count += 1;
localStorage.setItem("state", JSON.stringify(state));

const raw = localStorage.getItem("prefs");
const prefs = JSON.parse(raw);