Map的使用方式--iterator collections的使用

1 iteratorlai  来循环

      1.1

 public static void main(String[] args) {  // TODO Auto-generated method stub  Map map = new HashMap();  map.put("drink", "1");  map.put("hello", "3");  map.put("food", "2");  Iterator iterator = map.keySet().iterator();  while(iterator.hasNext()){   System.out.println(map.get(iterator.next()));  }

}

1.2

      Set entries = map.entrySet( );  Iterator iterator = entries.iterator( );  while(iterator.hasNext( )) {   Map.Entry entry =(Map.Entry)iterator.next();   Object key = entry.getKey( );   Object value = entry.getValue();   System.out.println("Key:"+key);   System.out.println("/n"+entry); //food=2  }

2 Collections 得到最大最小值

  Collection collection = map.values();//返回数值

Set sets= map.keySet();System.out.println(Collections.max(sets));//key的最大值

Collection collection = map.values();

System.out.println(Collections.max(collection));//value的最大值