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.
extend.dart
abstract class Dog {
void walk() {
print('walking...');
}
}
Subclass
The subclass can @override the behavior of the superclass.
extend.dart
class Pug extends Dog {
String breed = 'pug';
@override
void walk() {
super.walk();
print('I am tired. Stopping now.');
}
}