hphp/hack/manual/hsl/Functions/HH.Lib.Math/mean.md
:::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 the arithmetic mean of the numbers in the given container
namespace HH\Lib\Math;
function mean(
Container<num> $numbers,
): ?float;
Math\sum().Math\max().Math\min().Container<num>$numbers?float$v = vec[1, 2, 3, 4, 5];
$mean = Math\mean($v);
echo "Mean of the array is $mean \n"; // Output: Mean of the array is 3