package Map.Demo; import java.util.HashMap; import java.util.Iterator; import java.util.Set; public class HashMapDemo { public static void main(String[] args) { /* * 将学生对象和学生的归属地通过键与值储存到map集合中 * * */ HashMap<Students, String> hm=new HashMap<>(); hm.put(new Students("lisi", 38),"北京"); hm.put(new Students("zhaoliu", 24),"上海"); hm.put(new Students("xiaoqiang", 31),"沈阳"); hm.put(new Students("wangcai", 28),"大连"); hm.put(new Students("zhaoliu", 24),"铁岭"); // Set<Students> keySet=hm.keySet(); // Iterator<Students> it=keySet.iterator(); Iterator<Students> it=hm.keySet().iterator();//等于前两句 while(it.hasNext()) { Students key=it.next(); String value=hm.get(key); System.out.println(key.getName()+":"+key.getAge()+"---"+value); } } }