Grouping sequencial numbers in a subarray

group_sequencial.php

$elements = [1, 2, 3, 4, 6, 7, 10, 15, 20, 21, 22, 33];
$groups = [];
$groupKey = 0;

for ($i = 0; $i < count($elements) ; $i++) {
    $currenElement = $elements[$i];
    $nextElement = $elements[$i + 1];

    $groups[$groupKey][] = $currenElement;
    if (($currenElement + 1) != $nextElement) {
        $groupKey++;
    }
}

print_r($groups);