array_gcd, array_lcm (PHP)

array_gcdlcm.php

<?php

function array_gcd(array $arr): int
{
    return array_reduce($arr, function (int $a, int $b): int {
        while ($b) {
            $r = $a % $b;
            $a = $b;
            $b = $r;
        }
        return $a;
    }, $arr[0]);
}

function array_lcm(array $arr): int
{
    return array_reduce($arr, function (int $a, int $b): int {
        return $a / array_gcd([$a, $b]) * $b;
    }, 1);
}

echo array_lcm(range(1, 6)); // outputs 60