java中遍历MAP的几种方法

来源：互联网发布：php开发oa系统编辑：程序博客网时间：2024/05/17 01:24

Map<String,String> map=new HashMap<String,String>();  map.put("username", "qq");   map.put("passWord", "123");  map.put("userID", "1");   map.put("email", "qq@qq.com");

第一种用for循环

for(Map.Entry<String, String> entry:map.entrySet()){        System.out.println(entry.getKey()+"--->"+entry.getValue());   }

第二种用迭代

Set set = map.entrySet();        Iterator i = set.iterator();        while(i.hasNext()){          Map.Entry<String, String> entry1=(Map.Entry<String, String>)i.next();        System.out.println(entry1.getKey()+"=="+entry1.getValue());   }

用keySet()迭代

Iterator it=map.keySet().iterator();   while(it.hasNext()){        String key;        String value;        key=it.next().toString();        value=map.get(key);        System.out.println(key+"--"+value);   }

用entrySet()迭代

Iterator it=map.entrySet().iterator();          System.out.println( map.entrySet().size());   String key;          String value;   while(it.hasNext()){           Map.Entry entry = (Map.Entry)it.next();                  key=entry.getKey().toString();                  value=entry.getValue().toString();                  System.out.println(key+"===="+value);                    }

来自：http://apps.hi.baidu.com/share/detail/18322217