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chunk

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 vec containing the given Traversable split into chunks of the given size

namespace HH\Lib\Keyset;

function chunk<Tv as arraykey>(
  Traversable<Tv> $traversable,
  int $size,
): vec<keyset<Tv>>;

If the given Traversable doesn't divide evenly, the final chunk will be smaller than the specified size. If there are duplicate values in the Traversable, some chunks may be smaller than the specified size.

Time complexity: O(n) Space complexity: O(n)

Parameters​

Returns​

  • vec<keyset<Tv>>

Examples​

$result = Keyset\chunk(vec[1,2,3,4,5,6],3);
print_r($result);
//result: [keyset[1,2,3], keyset[4,5,6]]

$result = Keyset\chunk(vec[1,2,2,3,4,5],3);
print_r($result);
//result: [keyset[1,2], keyset[3,4,5]]