Dart Mixins and Extension Methods

mixin Swimmable {
  void swim() => print('Swimming!');
}

mixin Flyable {
  void fly() => print('Flying!');
}

class Duck extends Animal with Swimmable, Flyable {
  Duck() : super('Duck');
}

mixin Jumpable on Animal {
  void jump() => print('$name jumps!');
}

class Rabbit extends Animal with Jumpable {
  Rabbit() : super('Rabbit');
}

extension StringExtensions on String {
  String capitalize() {
    if (isEmpty) return this;
    return '${this[0].toUpperCase()}${substring(1)}';
  }

  bool get isEmail => contains('@') && contains('.');
}

void main() {
  print('hello'.capitalize());    // "Hello"
  print('test@email.com'.isEmail); // true
}