Notice: Undefined index: $controller in C:\wamp64\www\mvc\index.php on line 7

Notice: Undefined index: $controller in C:\wamp64\www\mvc\index.php on line 7。

<?php
  require_once ('function.php');
  $controllerAllow=array('test','index');
  $methodAllow=array('test','index','show');
//  $controller=$_GET['controller'];
//  $method=$_GET['method'];
  $controller=in_array($_GET['controller'],
      $controllerAllow)?daddslashes($_GET['controller']):'index';
  $method=in_array($_GET['method'],
      $methodAllow)?daddslashes($_GET['controller']):'index';;
  C($controller,$method);
  
  
  一直运行失败