HH\ImmMap::containsKey

Determines if the specified key is in the current ImmMap

public function containsKey(
  mixed $key,
): bool;

This function is interchangeable with contains().

Guide

• Constraints

Parameters

• mixed $key

Returns

• bool - true if the specified key is present in the current ImmMap; false otherwise.

Examples

See [Map::containsKey](</hack/reference/class/Map/containsKey/#examples>) for usage examples.