class Challenge {  const UPLOAD_DIRECTORY = './solutions/';  private $file;  private $whitelist;  public function __construct($file) {    $this->file = $file;    $this->whitelist = range(1, 24);    //生成包含1-24的数组  }  public function __destruct() {    if (in_array($this->file['name'], $this->whitelist)) {    //验证邮箱的名字但是并没有验证上传文件的文件类型      move_uploaded_file(        $this->file['tmp_name'],        self::UPLOAD_DIRECTORY . $this->file['name']      );    }  }}$challenge = new Challenge($_FILES['solution']);