👩‍👦 Extend

Superclass

The superclass or parent class contains the behaviors that is shared by all subclasses. The abstract keyword is used to indicate that the class is not meant to be instantiated, but rather to be inherited from.

abstract class Dog {
  void walk() {
    print('walking...');
  }
}

Subclass

The subclass can @override the behavior of the superclass.

class Pug extends Dog {
  String breed = 'pug';

  @override
  void walk() {
    super.walk();
    print('I am tired. Stopping now.');
  }
}