Storage.length
The length
read-only property of the Storage
interface returns an integer representing the number of data items stored in the Storage
object.
Syntax
var aLength = storage.length;
Return value
An integer
Example
The following function adds three data items to the local storage for the current domain, then returns the number of items in the storage:
function populateStorage() { localStorage.setItem('bgcolor', 'yellow'); localStorage.setItem('font', 'Helvetica'); localStorage.setItem('image', 'cats.png'); localStorage.length; // should return 3 }
Note: For a real world example, see our Web Storage Demo.
Specifications
Specification | Status | Comment |
---|---|---|
Web Storage The definition of 'length' in that specification. |
Recommendation |
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|
localStorage | 4 | 3.5 | 8 | 10.50 | 4 |
sessionStorage | 5 | 2 | 8 | 10.50 | 4 |
Feature | Android | Firefox Mobile (Gecko) | IE Phone | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|
Basic support | 2.1 | ? | 8 | 11 | iOS 3.2 |
All browsers have varying capacity levels for both localStorage and sessionStorage. Here is a detailed rundown of all the storage capacities for various browsers.
Note: since iOS 5.1, Safari Mobile stores localStorage data in the cache folder, which is subject to occasional clean up, at the behest of the OS, typically if space is short.
See also
License
© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-us/docs/web/api/storage/length