takeWhile
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.
Returns a Map containing the keys and values of the current Map up to
but not including the first value that produces false when passed to the
specified callback
public function takeWhile(
(function(Tv): bool) $callback,
): Map<Tk, Tv>;
The returned Map will always be a proper subset of the current Map.
Parameters
(function(Tv): bool) $callback