增强For遍历Map集合的要点！

import java.util.*;
class ForTest{
public static void main(String[] args){
HashMap<Integer,String>hm=new HashMap<Integer,String>();
hm.put(1,"xxc1");
hm.put(2,"xxc2");
hm.put(3,"xxc3");
/*Set<Integer>s=hm.keySet();
for(Integer i:s){
System.out.println(i+"=="+hm.get(i));
}*/
Set<Map.Entry<Integer,String>>s=hm.entrySet();
for(Map.Entry<Integer,String> me:s){
System.out.println(me.getKey()+"========"+me.getValue());
}
}
}