FormData.has()
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
JavaScript
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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:
JavaScript
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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
:
JavaScript
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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
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|
Basic support | 50.0 | 39.0 (39.0) | No support | (Yes) | No support |
Available in web workers | 50.0 | 39.0 (39.0) | No support | (Yes) | No support |
Feature | Android | Android Webview | Firefox Mobile (Gecko) | Firefox OS (Gecko) | IE Mobile | Opera Mobile | Safari Mobile | Chrome for Android |
---|---|---|---|---|---|---|---|---|
Basic support | No support | 50.0 | (Yes) | (Yes) | No support |
(Yes) |
No support | 50.0 |
Available in web workers | No support | 50.0 | (Yes) | (Yes) | No support | (Yes) | No support | 50.0 |
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/formdata/has