Dart Island · Level 7
Inheritance & Polymorphism
Inheritance lets one class extend another, gaining all its fields and methods. Polymorphism means a child object can be used wherever a parent is expected — each responding in its own way.
12 games from family trees to full method-resolution tracing.
12 games from family trees to full method-resolution tracing.
Core idea
When class Dog extends Animal, Dog gets everything Animal has, and can also add or change behaviour.
class Animal {
void speak() => print('...');
}
class Dog extends Animal {
@override
void speak() => print('Woof!');
}
Animal a = Dog();
a.speak(); // Woof! ← polymorphism
- extends — inherit from a parent class
- @override — replace a parent method with your own
- super — call the parent's version of a method
- abstract — a class that cannot be instantiated directly
Progress
0 / 12 mini-games solved
Stage 1
Family Tree
Drag child classes under their parent on a tree diagram.
1. Select a class. 2. Click the slot it extends from.
Animal