26. Remove Duplicates from Sorted Array

class Solution {

    /**
     * @param Integer[] $nums
     * @return Integer
     */
    function removeDuplicates(&$nums) {
        $unique = [];
        foreach($nums as $key => $num){
            if (in_array($num, $unique)){
                unset($nums[$key]);
            } else {
                $unique[] = $num;
            }
        }

        return count($nums);
    }
}