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zip

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 where each element is a tuple (pair) that combines, pairwise, the elements of the two given Traversables

namespace HH\Lib\Vec;

function zip<Tv, Tu>(
  Traversable<Tv> $first,
  Traversable<Tu> $second,
): vec<(Tv, Tu)>;

If the Traversables are not of equal length, the result will have the same number of elements as the shortest Traversable. Elements of the longer Traversable after the length of the shorter one will be ignored.

Time complexity: O(min(m, n)), where m is the size of $first and n is the size of $second Space complexity: O(min(m, n)), where m is the size of $first and n is the size of $second

Parameters​

Returns​

  • vec<(Tv, Tu)>

Examples​

$example_vec1 = vec[1,2,3,4,5];
$example_vec2 = vec[11,17,23,44,55];

$result = Vec\zip($example_vec1, $example_vec2);
print_r($result);
//result: [[1, 11], [2,17], [3,23], [4, 44], [5,55]]

$example_vec3 = vec[6,7];
$result = Vec\zip($example_vec1, $example_vec3);
print_r($result);
//result: [[1,6], [2,7]]