Range

:::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 a new vec containing the range of numbers from $start to $end inclusive, with the step between elements being $step if provided, or 1 by default

namespace HH\Lib\Vec;

function range<Tv as num>(
  Tv $start,
  Tv $end,
  ?Tv $step = NULL,
): vec<Tv>;

If $start > $end, it returns a descending range instead of an empty one.

If you don't need the items to be enumerated, consider Vec\fill.

Time complexity: O(n), where n is the size of the resulting vec Space complexity: O(n), where n is the size of the resulting vec

Parameters

• Tv $start
• Tv $end
• ?Tv $step = NULL

Returns

• vec<Tv>

Examples

$result = Vec\range(1, 10, 1);
print_r($result);
//result: [1,2,3,4,5,6,7,8,9,10]

$result = Vec\range(1, 10, 2);
print_r($result);
//result: [1,3,5,7,9]

$result = Vec\range(1, 10, 3);
print_r($result);
//result: [1,4,7,10]