Modern JavaScript

Local Storage

localStorage saves small amounts of data in the browser. It stays after the page is closed, which is perfect for settings like dark mode.

localStorage.setItem("theme", "dark");
console.log(localStorage.getItem("theme")); // "dark"
localStorage.removeItem("theme");

// store objects as JSON
const cart = [{ id: 1, qty: 2 }];
localStorage.setItem("cart", JSON.stringify(cart));
const saved = JSON.parse(localStorage.getItem("cart") ?? "[]");