object(PDO)#2 (0) { }

class User{
    protected $conn;
    protected $handle;

    private $host = 'localhost';
    private $db   = 'test';
    private $user = 'root';
    private $pass = '';
    private $charset = 'utf8';

    private $opt = [
    PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
    PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
    PDO::ATTR_EMULATE_PREPARES   => false,
    ];

    public function __construct()
    {
        $this->conn = new PDO("mysql:host=$this->host;dbname=$this->db;charset=$this->charset", $this->user, $this->pass, $this->opt);
    }

    public static function register($table, $data = array())
    {
        var_dump($this->conn);
        exit;
    }
}