Contains

:::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 whether a value is in the current Set

public function contains(
  arraykey $m,
): bool;

Parameters

• arraykey $m

Returns

• bool - true if the value is in the current Set; false otherwise.