JAVA问题之List<List<E>>

 1 package listinnerlist.main;
 2 
 3 import java.util.*;
 4 
 5 public class ListInnerList {
 6     public static void main(String[] args){
 7         LinkedList<LinkedList<String>> li=new LinkedList<LinkedList<String>>();
 8         li.add(new LinkedList<String>());
 9         (li.get(0)).add("String");
10         System.out.println(li.get(0));
11         System.out.println((li.get(0)).get(0));
12     }
13 }