localStorage / sessionStorage
property
Web Storage APIs for storing data in the browser. localStorage persists; sessionStorage is per-tab.
Syntax
localStorage.setItem(key, value) localStorage.getItem(key)
Example
javascript
// Save data
localStorage.setItem('username', 'Alice');
localStorage.setItem('settings', JSON.stringify({ theme: 'dark' }));
// Read data
const name = localStorage.getItem('username'); // 'Alice'
const settings = JSON.parse(localStorage.getItem('settings'));
// Remove
localStorage.removeItem('username');
localStorage.clear(); // remove all
// Session (clears when tab closes)
sessionStorage.setItem('cart', JSON.stringify(cartItems));