在Scala中具有相同行为的几个case类

case class Circle(radius: Double)
case class Rectangle(width: Double, height: Double)
case class Triangle(base: Double, height: Double)

object ShapeCalculator {
  def area(shape: Any): Double = shape match {
    case Circle(radius) => Math.PI * radius * radius
    case Rectangle(width, height) => width * height
    case Triangle(base, height) => 0.5 * base * height
    case _ => throw new IllegalArgumentException("Unknown shape")
  }
}

// 使用示例
val circle = Circle(5)
val rectangle = Rectangle(4, 6)
val triangle = Triangle(3, 4)

println(s"Circle area: ${ShapeCalculator.area(circle)}")
println(s"Rectangle area: ${ShapeCalculator.area(rectangle)}")
println(s"Triangle area: ${ShapeCalculator.area(triangle)}")

def area(shape: Any): Double = shape match {
  case Circle(radius) => Math.PI * radius * radius
  case Rectangle(width, height) => width * height
  case Triangle(base, height) => 0.5 * base * height
  case _ => throw new IllegalArgumentException("Unknown shape")
}