HH\Map::reserve

Reserves enough memory to accommodate a given number of elements.

Description

public function reserve(
  int $sz,
): void

Reserves enough memory to accommodate a given number of elements.

Reserves enough memory for sz elements. If sz is less than or equal to the current capacity of this Map, this method does nothing.

Parameters

  • int $sz - The pre-determined size you want for the current Map.

Examples

This example reserves space for 1000 elements and then fills the Map with 1000 integer keys and values:

<?hh

namespace Hack\UserDocumentation\API\Examples\Map\Reserve;

const int MAP_SIZE = 1000;

$m = Map {};
$m->reserve(MAP_SIZE);

for ($i = 0; $i < MAP_SIZE; $i++) {
  $m[] = Pair {$i, $i * 10};
}

var_dump($m);