object Calculate {

  case class Calculate(a: Int, b: Int) {

    def add(): Int = a + b

    def subtract(): Int = a - b

    def multiply(): Int = a * b

    def divide(): Int = a / b
  }

  def main(args: Array[String]): Unit = {
    val c = Calculate(7, 5)
    println("加法:" + c.add())
    println("减法:" + c.subtract())
    println("乘法:" + c.multiply())
    println("除法:" + c.divide())
  }

}