Dart by Example: Mixins

import 'dart:math';
class Position {
  int x;
  int y;
  double distanceTo(Position other) {
    var dx = other.x - x;
    var dy = other.y - y;
    return sqrt(dx * dx + dy * dy);
  }
}
class Square {
  int width;
  int height;
  int get area => width * height;
}
// Classes can be mixed in using 'with'
class SquareView extends Square with Position {}
main() {
  var origin = new Position()
    ..x = 0
    ..y = 0;
  var square = new SquareView()
    ..x = 5
    ..y = 5
    ..width = 10
    ..height = 10;
  print(square.distanceTo(origin));
  print(square.area);
}
 

$ dart mixins.dart
7.0710678118654755
100

by @jryanio | source | license