Learning Dart - 3 Use optional parameters (instead of overloading)

main.dart

import 'dart:math';

class Rectangle {
  int width;
  int height;
  Point origin;

  Rectangle({this.origin = const Point(0, 0), this.width = 0, this.height = 0});

  @override
  String toString() =>
      "Origin: ${origin.x}, ${origin.y}, width: $width, height: $height";
}

main() {
  print(Rectangle(origin: Point(5, 10), width: 50, height: 40));
  print(Rectangle(origin: Point(5, 10), width: 50));
  print(Rectangle(origin: Point(5, 10)));
  print(Rectangle());
}