The has() method of the FormData interface returns a boolean stating whether a FormData object contains a certain key.

Note: This method is available in Web Workers.

Syntax

formData.has(name);

Parameters

name
A USVString representing the name of the key you want to test for.

Returns

A Boolean.

Example

The following line creates an empty FormData object:

var formData = new FormData();

The following snippet shows the results of testing for the existence of username in the FormData object, before and after appending a username value to it with FormData.append:

formData.has('username'); // Returns false
formData.append('username', 'Chris');
formData.has('username'); // Returns true

Specifications

Specification Status Comment
XMLHttpRequest
The definition of 'has()' in that specification.
Living Standard  

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support50 No39 No Yes No
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support ?50 No Yes Yes No ?

See also

Document Tags and Contributors

Last updated by: ExE-Boss,