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[Java教程]【Java学习笔记】Map借口的子接口


存储在HashMap集合中的元素,必须覆盖hashCode和equals方法(与HashSet类似)

 

 

 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      * 将学生对象和学生的归属地通过键与值存储到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), "沈阳");17     hm.put(new Student("wangcai",38), "大连");18     hm.put(new Student("zhaoliu",24), "铁岭");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 }