import java.util.ArrayList;
import java.util.List;
public class Demo{
public static void main(String[] args) {
List<String> l1=new ArrayList();
l1.add("成员1");
List<? extends Object>l2=new ArrayList<Number>();
List<?>l3=l1;
//l3不允许修改和添加
//l2.add(123);
//l1.set(0, "成员改变");
System.out.println("l3：" l3.get(0));
List<? extends List> l2=new ArrayList<List>();
List<? super List> l3=new AttayList<Object>();
Demo<?>d;
}
}
public class Demo{
public static void main(String[] args) {
}
}
class Father<T,E>{
T t;
public Father(T t){
this
}.t=t;
}
interface TestInter
