class?E
{
???public?$age?=?0;
???public?$username?=?"";
???public?$obj?=?null;

???public?function?__clone()
???{
???????//?TODO:?Implement?__clone()?method.
???????$this->obj?=?clone?$this->obj;
???}
}
class?F?{
???public?$sex?=?0;
}
$e?=?new?E();
$e->obj?=?new?F();
$f?=?clone?$e;
$f->obj->sex?=?8;
var_dump($f->obj->sex);//int(8)，為什么還是8，應該為0啊