How to create private methods that can be redefined in subclasses in Dart?

Question

Whenever I define a private method like this:

class ParentClass {

  sayHi() { _initiateGreeting(); }
  _initiateGreeting() { print("I'm a parent class"); }

}

It is not possible to redefine it in a subclass:

class ChildClass extends ParentClass {
  _initiateGreeting() { print("I'm a child class"); } // redefining the method
}

Now if I create an instance of a ChildClass and call sayHi() method, then it is the private method from a ParentClass which actually gets called:

var child = new ChildClass();
child.sayHi(); // outputs "I'm a parent class"

If, however, _initiateGreeting() is made public everywhere (that is, stripped off the _) then calling child.sayHi() results in the output I'm a child class.

Why? How do I redefine a private method so that it gets called in a subclass?

Answer 1

Private member can be seen as library member. Inside a library there are no difference between members with or without a prepending underscore.

So if you're in the same library you should be able to redefined the method in subclass.