HH\Pair::containsKey

Checks whether a provided key exists in the current Pair

public function containsKey<Tu super int>(
  Tu $key,
): bool;

This will only return true for provided keys of 0 and 1 since those are the only two keys that can exist in a Pair.

Parameters

  • Tu $key

Returns

  • bool - true if the provided key exists in the Pair; false otherwise. This will only return true if the provided key is 0 or 1.

Examples

$p = Pair {'foo', -1.5};

// Prints "true", since index 0 is the first value
var_dump($p->containsKey(0));

// Prints "true", since index 1 is the second value
var_dump($p->containsKey(1));

// Prints "false", since a Pair only has index 0 and index 1
var_dump($p->containsKey(2));
Output
bool(true)
bool(true)
bool(false)