$ _GET未设置

Question

打印$_GET时出现错误：

Notice: Undefined variable: _GET 

测试代码：

echo "query string: ".($_SERVER['QUERY_STRING']);
print_r($_GET);

测试网址：

http://localhost/?foo=bar

结果输出为：

query string: foo=bar
Notice: Undefined variable: _GET in C:\Users\DGmoN\Google Drive\Code\Web\CMS2\index.php on line 3