FirstValue

:::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. :::

Returns the first value in the current Map

public function firstValue(): ?Tv;

Returns

• ?Tv - The first value in the current Map, or null if the Map is empty.

Examples

The following example gets the first value from a Map. An empty Map will return null as its first value.

$m = Map {
  'red' => '#ff0000',
  'green' => '#00ff00',
  'blue' => '#0000ff',
  'yellow' => '#ffff00',
};
\var_dump($m->firstValue());

$m = Map {};
\var_dump($m->firstValue());