How to copy an object by value, not by reference [duplicate]

Answer 1

You need to do a deep copy from user to usercopy, and then after your login you can reassign your userCopy reference to user.

User userCopy = new User();
userCopy.Age = user.Age
userCopy.ID = user.ID

foreach(...) 
{ 
  user.Age = 1; 
  user.ID = -1; 

  UserDao.Update(user)     

  user = userCopy;       
}