Flutter/Dart：使用私有变量获取和设置

Question

if I read that setters and getters have to be explicity developed in Dart only when you want to do something more than only retrieve those values. But if I have private variables, like:

Class User {
  User _user;
  String _password;
}

How can I access to those private variables? Even if I implement the set password like

 set password(String value) => _password = value;

It will of course give me an "error".

Answer 1

If you want public getter/setter what's the point of having private variable for that?

Just make it a public variable and be done.

If you insist having a private variable with public access, then you still need to add the getter and setter.

Answer 2

Private variable is import due to some reasons, If you conditionally set or get your Class property values then setter and getter is important on private variables. Example given below:

   class User {

       int _id;
       String _firstName;
       String _password;

      int get id => _id;

      set id(int value) {
        _id = value;
      }

      String get firstName => _firstName;

      set firstName(String value) {
        if(value.length > 7)
           _firstName = value;
      }

      String get password => _password;

      set password(String value) {
         if(some condition against this value like password)
            _password = value;
      }
   }

Note: you can set condition in getter like setter that I have given in above example.