JavaScript storage object
The Web Storage API provides two storage objects
sessionStorage
(session storage) and
localStorage
(local storage) to add, delete, modify, and query web page data.
- localStorage is used to save the data of the entire website for a long time, and the saved data has no expiration time until it is manually removed. The localStorage property is read-only.
- sessionStorage is used to temporarily save the data of the same window (or tab), which will be deleted after closing the window or tab.
storage object method
| parameter | describe |
|---|---|
| key(n) | Returns the name of the nth key in the storage object |
| getItem(keyname) | Returns the value for the specified key |
| setItem(keyname, value) | Add key and value, if the corresponding value exists, update the value corresponding to the key. |
| removeItem(keyname) | remove key |
| clear() | Clear all keys in the storage object |
1.localStorage
Syntax: window.localStorage
Save Data Syntax: localStorage.setItem("key", "value");
Read Data Syntax: var lastname = localStorage.getItem("key");
Delete Data Syntax:localStorage.removeItem("key");
2.sessionStorage
Syntax: window.sessionStorage
save data Syntax: sessionStorage.setItem("key", "value");
read data Syntax: var lastname = sessionStorage.getItem("key");
delete data for specified key Syntax:: sessionStorage.removeItem("key");
delete all data:sessionStorage.clear();