【Java學習筆記】Map借口的子接口----HashMap，map和hashmap的區別

【Java學習筆記】Map借口的子接口----HashMap，map和hashmap的區別

存儲在HashMap集合中的元素，必須覆蓋hashCode和equals方法（與HashSet類似）

 1 import java.util.HashMap;
 2 import java.util.Iterator;
 3 
 4 import cn.itcast.p2.bean.Student;
 5 
 6 public class HashMapDemo {
 7 
 8     public static void main(String[] args) {
 9         /*
10          * 將學生對象和學生的歸屬地通過鍵與值存儲到map集合中
11          */
12         HashMap<Student,String> hm = new HashMap<Student,String>();
13         
14         hm.put(new Student("lisi",38), "北京");
15         hm.put(new Student("zhaoliu",24), "上海");
16         hm.put(new Student("xiaoqiang",31), "沈陽");
17         hm.put(new Student("wangcai",38), "大連");
18         hm.put(new Student("zhaoliu",24), "鐵嶺");
19         
20         Iterator<Student> it = hm.keySet().iterator();
21         while (it.hasNext())
22         {
23             Student key = it.next();
24             String value = hm.get(key);
25             System.out.println(key.getName()+":"+key.getAge()+"--"+value);
26         }
27 
28     }
29 
30 }