Map遍历两种方式

Java代码
    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
Java代码

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

第二种用迭代

用entrySet();
    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);
    }