遍历map的几种方式

userList.put("1",new User("1","zhangsan","ddd"));
userList.put("2",new User("2","lisi","ddd"));
userList.put("3",new User("3","wanwu","ddd"));

//1. userList.value()

for(User user : userList.value()){
if(userName.equals(user.getUserName()) $$ password.equals(userPass)){
System.out.println("登录成功");
break;
}
}

//2.userList.KeySet() 得到key的集合

for(String key : userList.keySet()){
System.out.println("key-->" + key + "value-->" + userList.get(key).getUserName());
}

//3.Iterator    Map转为set
Iterator<Map.Entry<String,User>> it = userList.entrySet().iterator();
while(it.hasNext()){
Map.Entry<String,User> entry = it.next();
System.out.println("key-->" + entry.getKey + "value-->" + entry.getValue().getUserName());
}

//4.userList.entrySet()   Map转为set
for(Map.Entry<String,User> entry : userList.entrySet()){
System.out.println("key-->" + entry.getKey + "value-->" + entry.getValue().getUserName())
}