QuickSort algorithm in PHP

sort.php

<?php

class sort
{

    public function quicksort(array $data, $left, $right)
    {
        if ($left < $right) {
            $splitpos = $this->split($data, $left, $right);
            $data = $this->quicksort($data, $left, $splitpos -1);
            $data = $this->quicksort($data, $splitpos +1, $right);
        }
        return $data;
    }

    public function split(array &$data, $left, $right)
    {
        $pivot = $right;
        $pivotValue = $data[$pivot];

        do {
            while ($data[$left] < $pivotValue && $left < $right){
                $left++;
            }
            while ($data[$right] >= $pivotValue && $left < $right){
                $right--;
            }
            $temp = $data[$left];
            $data[$left] = $data[$right];
            $data[$right] = $temp;
        }
        while($left < $right);

        $temp = $data[$left];
        $data[$left] = $data[$pivot];
        $data[$pivot] = $temp;
        return $left;
    }
}


$sort = new sort();
$data = [4,2,3,7,6,9,1,8,8,9,1,3];
print_r($sort->quicksort($data,0, count($data) - 1));