Inheritance

This lesson covers inheritance, which builds a new class on top of an existing one.

You inherit by writing class Child extends Parent { ... }. Adding @override lets you replace a method of the parent class.

The sample code inherits class Animal with class Dog extends Animal and overrides speak() with dog-specific behaviour.

A common early stumble is passing the constructor along. A child class constructor has to call super(name) to run the parent's initialisation.

In professional work, it is common in Flutter to build a custom widget with a shared style by inheriting from an existing one.

📖 Reference code

class Animal {
  String name;
  Animal(this.name);
  String speak() => '$name is making a sound.';
}

class Dog extends Animal {
  Dog(String name) : super(name);
  @override
  String speak() => '$name: Woof!';
}

void main() {
  var dog = Dog('Rex');
  print(dog.speak());
}

✍️ Your code

Type your code, then press "Run"

🧪 This site can't compile or run Dart directly, so it checks on the spot whether what you typed matches the reference code (scoring happens entirely in your browser — nothing is sent anywhere).