The setItem()
method of the Storage
interface, when passed a key name and value, will add that key to the given Storage
object, or update that key's value if it already exists.
Syntax
storage.setItem(keyName, keyValue);
Parameters
keyName
- A
DOMString
containing the name of the key you want to create/update. keyValue
- A
DOMString
containing the value you want to give the key you are creating/updating.
Return value
Exceptions
setItem()
may throw an exception if the storage is full. Particularly, in Mobile Safari (since iOS 5) it always throws when the user enters private mode. (Safari sets the quota to 0 bytes in private mode, unlike other browsers, which allow storage in private mode using separate data containers.) Hence developers should make sure to always catch possible exceptions from setItem()
.
Example
The following function creates three data items inside local storage.
function populateStorage() { localStorage.setItem('bgcolor', 'red'); localStorage.setItem('font', 'Helvetica'); localStorage.setItem('image', 'myCat.png'); }
Note: To see this used within a real world example, see our Web Storage Demo.
Specifications
Specification | Status | Comment |
---|---|---|
HTML Living Standard The definition of 'Storage.setItem' in that specification. |
Living Standard |
Browser compatibility
The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
setItem | Chrome Full support 4 | Edge Full support 12 | Firefox Full support 3.5 | IE Full support 8 | Opera Full support 10.5 | Safari Full support 4 | WebView Android Full support ≤37 | Chrome Android Full support 18 | Firefox Android Full support 6 | Opera Android Full support 11 | Safari iOS Full support 3.2 | Samsung Internet Android Full support 1.0 |
Legend
- Full support
- Full support