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isSubclassOf

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.

( excerpt from http://php.net/manual/en/reflectionclass.issubclassof.php )

public function isSubclassOf(
  mixed $class,
): bool;

Checks if the class is a subclass of a specified class or implements a specified interface.

Parameters​

  • mixed $class

Returns​

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