IsSupported

:::info[Note] This is a point-in-time snapshot of the API documentation from January 2026. Going forward, we will not be maintaining a public copy of these references, and recommend users to refer to the built-in signature helpers available in the Hack LSP instead for complete and up-to-date information. :::

Checks if the asked feature is supported for the specified version

public function isSupported(
  string $feature,
  string $version,
): bool;

Parameters

• string $feature - The feature to test. See the example of DOMImplementation::hasFeature() for a list of features.
• string $version - The version number of the feature to test.

Returns

• bool - - Returns TRUE on success or FALSE on failure.