FormData: has() method

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

Note: This feature is available in Web Workers

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

Specification
XMLHttpRequest Standard
# dom-formdata-has

Browser compatibility

BCD tables only load in the browser

See also