BUG问题：

 *  Fatal error: Uncaught Error: Unsupported operand types in D:\phpstudy_pro\WWW\qx.com\app\controllers\admin\transaction.php:49
 *  Stack trace: #0 D:\phpstudy_pro\WWW\qx.com\vendor\noahbuscher\macaw\Macaw.php(97): admin\Transaction->add()
 *                   #1 D:\phpstudy_pro\WWW\qx.com\index.php(64): NoahBuscher\Macaw\Macaw::dispatch()
 *                   #2 {main} thrown in D:\phpstudy_pro\WWW\qx.com\app\controllers\admin\transaction.php on line 49

解决方案：
修改错误代码=>数组无法直接进行四则运算，需要遍历后才能