How to use this in a dart constructor with private variables

Question

When I try to create a constructor in dart like Student(this._name) it doesn't work with private variables.

I have already tried using setters but it doesn't work either.

    class Student{

    var _id;
    var _name;

    Student(this.id, this.name);

    void set id(int id) => _id = id;
    void set name(String name) => _name = name;

    }

Answer 1

This is not supported because it would expose private implementation to the outside.

If you'd rename var _id; to var _userId; you would break code that uses your class just by renaming a private field.
See instead the comment below my answer.

  class Student{

    var _id;
    var _name;

    Student({this._id, this._name}); // error

    void set id(int id) => _id = id;
    void set name(String name) => _name = name;
  }

The alternative

  class Student{

    var _id;
    var _name;

    Student({int id, String name}) : _id = id, _name = name;

    void set id(int id) => _id = id;
    void set name(String name) => _name = name;
  }

Answer 2

You can use this notation

class Student {
  String _id;
  String _name;

  Student({required String id, required String name})
      : _id = id,
        _name = name;
}