FormData: has() method

{{APIRef("XMLHttpRequest API")}} {{AvailableInWorkers}}

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

Syntax

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 {{domxref("FormData.append", "append()")}}:

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

Specifications

{{Specifications}}

Browser compatibility

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See also

• Using FormData objects
• {{HTMLElement("Form")}}