Classes - Dart Programming

A class groups data and behavior. Rectangle(this.width, this.height) is the constructor shorthand.

Program

Play the program to build a rectangle and call its area method.

classes.dart

class Rectangle {
  final int width;
  final int height;
  Rectangle(this.width, this.height);
  int area() => width * height;
}

void main() {
  var rect = Rectangle(4, 3);
  print(rect.area());
}

class `class Rectangle` groups fields and methods.

this.x constructor `Rectangle(this.width, this.height)` assigns straight to fields.

arrow method `=>` is a one-expression method body.