keys
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 an ImmVector with the values being the keys of the current
Pair
public function keys(): ImmVector<int>;
This method will return an ImmVector with keys 0 and 1, and values 0 and
1, since the keys of a Pair are 0 and 1.
Returns
ImmVector<int>- anImmVectorcontaining the integer keys of the currentPairas values.
Examples
$p = Pair {'foo', -1.5};
\var_dump($p->keys());