| import 'dart:math' as math; | |
| class Circle implements Shape { | |
| Circle(this.radius); | |
| double calculateArea() => math.pi * radius * radius; | |
| final double radius; | |
| } | |
| class Square implements Shape { | |
| Square(this.length); | |
| double calculateArea() => length * length; | |
| final double length; | |
| } | |
| double calculateArea(Shape shape) => switch (shape) { | |
| Square(length: var l) => l * l, | |
| Circle(radius: var r) => math.pi * r * r | |
| }; | |
| expect(expected, actual) {} | |
| main() {} | |
| sealed class Shape { | |
| double calculateArea(); | |
| } |