HH\Vector::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 the current Vector, this method does nothing.

If $sz is less than zero, an exception is thrown.

Parameters

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

Examples

This example reserves space for 1000 elements and then fills the Vector with 1000 integers:

<?hh

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

const int VECTOR_SIZE = 1000;

$v = Vector {};
$v->reserve(VECTOR_SIZE);

for ($i = 0; $i < VECTOR_SIZE; $i++) {
  $v[] = $i * 10;
}

var_dump($v);