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.
formData.has(name);
name
USVString
representing the name of the key you want to test for.A Boolean
.
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
Specification | Status | Comment |
---|---|---|
XMLHttpRequest The definition of 'has()' in that specification. | Living Standard |
Desktop | ||||||
---|---|---|---|---|---|---|
Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | |
Basic support | 50 | No | 39 | No | Yes | Yes |
Mobile | |||||||
---|---|---|---|---|---|---|---|
Android webview | Chrome for Android | Edge Mobile | Firefox for Android | Opera for Android | iOS Safari | Samsung Internet | |
Basic support | ? | 50 | No | Yes | Yes | No | ? |
© 2005–2018 Mozilla Developer Network and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/FormData/has