我们将创建一个具有属性scores数组和4个方法getScores、getAvarage、getHighest和getLowest的类：

class Scores
{
    private array $scores;

    /**
     * we pass the scores to the constructor and sort them
     * @param array $scores
     */
    public function __construct(array $scores)
    {
        sort($scores); // sort method uses the pointer
        $this->scores = $scores;
    }

    public function getScores(): array
    {
        return $this->scores;
    }

    public function getAvarage(): float
    {
        return array_sum($this->scores) / count($this->scores);
    }

    public function getHighest(): int
    {
        return end($this->scores); // we will return the last element of the array as it's already sorted ascending
    }

    public function getLowest(): ?int
    {
        return $this->scores[0] ?? null; // we will return the first element of the array if it's set, or null if it's not
    }
}

这是一个简单实现，如果有不清楚的地方请告诉我
编辑：下面是如何使用它：

$scores = new Scores([85, 70, 90, 95, 88]);

$avarage = $scores->getAvarage();
$highest = $scores->getHighest();
$lowest = $scores->getLowest();