scala中实现图形的子类列表

abstract class Shape {
  def area: Double
  def perimeter: Double
}

class Rectangle(width: Double, height: Double) extends Shape {
  override def area: Double = width * height
  override def perimeter: Double = 2 * (width + height)
}

class Circle(radius: Double) extends Shape {
  override def area: Double = math.Pi * radius * radius
  override def perimeter: Double = 2 * math.Pi * radius
}

val shapes: List[Shape] = List(
  new Rectangle(5, 3),
  new Circle(2.5),
  new Rectangle(4, 4)
)

// 计算所有图形的总面积
val totalArea: Double = shapes.map(_.area).sum

// 打印每个图形的周长
shapes.foreach(shape => println(s"Perimeter: ${shape.perimeter}"))

// 打印总面积
println(s"Total area: $totalArea")