list

Student s1=new Student("张三",1);		Student s2=new Student("李四",2);		Student s3=new Student("王五",2);				List
    
      list=new ArrayList
     
      ();		list.add(s1);		list.add(s2);		list.add(s3);					for(int i=0;i
     
    

map  遍历注意Entry()

HashMap
    
      map=new HashMap();		map.put(1, "aaa");		map.put(2, "bbb");		map.put(3, "ccc");		//map.remove(3);//		for(Map.Entry
     
       entry : map.entrySet())//遍历反法1//		{//			System.out.println(entry.getKey()+entry.getValue());//		}		//遍历方法2		for(Integer key :map.keySet())		{			System.out.println(key);		}				for(String val :map.values())		{			System.out.println(val);		}		//遍历方法3		Iterator
      
       
        > it=map.entrySet().iterator();		while(it.hasNext())		{			Map.Entry
        
          ma=it.next();			System.out.println(ma.getKey());			System.out.println(ma.getValue());		}	}