$_REQUEST两头的内容实践上仍是来历于$_GET $_POST $_COOKIE,弱点是没法判别变量究竟来自于get post 仍是cookie,对请求对照严厉的场所不合用。
php manual 写到:
Variables provided to the script via the GET, POST, and COOKIE input mechanisms, and which therefore cannot be trusted. The presence and order of variable inclusion in this array is defined according to the PHP variables_order configuration directive.