DOMTokenList.supports()

The supports() method of the DOMTokenList interface returns true if a given token is in the associated attribute's supported tokens. This method is intended to support feature detection.

Syntax

let trueOrFalse = element.supports(token)

Parameters

token

A DOMString containing the token to query for.

Returns

A Boolean indicating whether the token was found.

Example

let iframe = document.getElementById('display');

if (iframe.sandbox.supports('an-upcoming-feature')) {
  // support code for mystery future feature
} else {
  // fallback code
}

if (iframe.sandbox.supports('allow-scripts')) {
  // instruct frame to run JavaScript
  //
  // (NOTE: This feature is well-supported; this is just an example!)
  //
}

Specifications

Browser compatibility