1 public void QWER(){
2 Scanner sc=new Scanner(System.in);
3 HashMap hm=new HashMap();
4 Student stu=new Student();
5 // LinkedList liss=new LinkedList();//LinkeList类
6 String name;
7 int chengji;
8 for (int qq = 0; qq < 2; qq++) {
9 System.out.println("请输入学生姓名和成绩");
10 name=sc.next();
11 chengji=sc.nextInt();
12 stu=new Student(name,chengji);
13 hm.put(qq, stu);//映射
14 }
15 Set set =hm.entrySet();
16 Iterator it=set.iterator();
17 while(it.hasNext())
18 {
19 Map.Entry en=(Map.Entry)it.next();
20 Student dog =(Student)en.getValue();
21 System.out.println(en.getKey()+" "+en.getValue());
22 }
23 /**
24 * 换人实现
25 */
26
27
28 System.out.println("该数据");
29 int xiabiao=sc.nextInt();
30 name=sc.next();
31 chengji=sc.nextInt();
32 stu=new Student(name,chengji);
33 hm.put(xiabiao, stu);//映射
34
35
36
37 System.out.println("遍历");
38 System.out.println(hm.values());//遍历
39 System.out.println("集合个数");
40 /* System.out.println(hm.size());//显示集合个数
41 hm.clear();//清空
42 hm.put("q", 1);
43 hm.put("w", 2);
44 System.out.println("枚举");
45 System.out.println(hm.entrySet());//枚举
46 hm.put("q", 3);
47 System.out.println(hm.entrySet());//枚举
48 hm.remove("q");
49 System.out.println(hm.entrySet());//枚举
50
51 *
