- 题目是这样的:
- import java.util.*;
- public class CollectionTest {
- public static void main(String[] args) {
-
- TreeSet
-
- set = new TreeSet
-
- ();
- ArrayList
-
- list = new ArrayList
-
- ();
- Vector
-
- vector = new Vector
-
- ();
-
- for (int i = 0; i < 10; i++) {
- set.add(i);
- list.add(i);
- vector.add(i);
- }
- System.out.println("初始化后set里的值为:" + set.toString());
- System.out.println("初始化后list里的值为:" + list.toString());
- System.out.println("初始化后vector里的值为:" + vector.toString());
-
- for (int i = 0; i < 5; i++) {
- set.remove(i);
- list.remove(i);
- vector.remove(i);
-
- }
- System.out.println("此时set的值为" + set.toString());
- System.out.println("此时后list的值为" + list.toString());
- System.out.println("此时后vector的值为" + vector.toString());
-
- }
-
- }
-
-
-
-
-
-
复制代码 程序运行的结果:
初始化后 set里的值为:[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
初始化后list里的值为:[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
初始化后vector里的值为:[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
处理后set的值为[5, 6, 7, 8, 9]
处理后list 的值为[1, 3, 5, 7, 9]
处理后vector的值为[1, 3, 5, 7, 9] 看出来了吗,最后list和和vector得到结果不是想象的[[5, 6, 7, 8, 9]],而是[1, 3, 5, 7, 9]。
注解:
List 里两个方法:
public E remove(int index)。//每次删除一个元素,后面的元素自动全部向前移动;
public boolean remove(Object o)//这个删除对象
源码下载:http://file.javaxxz.com/2014/10/30/235543546.zip |