concat

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 Vector that is the concatenation of the values of the current Map and the values of the provided Traversable

public function concat<Tu super Tv>(
  Traversable<Tu> $traversable,
): Vector<Tu>;

The provided Traversable is concatenated to the end of the current Map to produce the returned Vector.

Guide

• Constraints

Parameters

• Traversable<Tu>$traversable - The Traversable to concatenate to the current Map.

Returns

• Vector<Tu> - The integer-indexed concatenated Vector.

Examples

This example creates new Vectors by concatenating the values in a Map with Traversables:

$m = Map {
  'red' => '#ff0000',
};

// Create a Vector by concating the values from $m with a Set
$v1 = $m->concat(Set {'#00ff00', '#0000ff'});

// Create a Vector by concating the values from $m with a Vector
$v2 = $m->concat(Vector {'#ffff00', '#663399'});

\var_dump($m->values()); // $m contains the value '#ff0000'
\var_dump($v1); // $v1 contains '#ff0000', '#00ff00', '#0000ff'
\var_dump($v2); // $v2 contains '#ff0000', '#ffff00', '#663399'