FormData: has() method
Baseline
Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since October 2018.
Note: This feature is available in Web Workers.
The has() method of the FormData interface returns whether a FormData object contains a certain key.
Syntax
js
has(name)
Parameters
name-
A string representing the name of the key you want to test for.
Return value
true if a key of FormData matches the specified name. Otherwise, false.
Examples
The following snippet shows the results of testing for the existence of username in a FormData object, before and after appending a username value to it with append():
js
formData.has("username"); // Returns false
formData.append("username", "Chris");
formData.has("username"); // Returns true
Specifications
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| XMLHttpRequest # dom-formdata-has |
Browser compatibility
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Legend
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- Full support
- Full support