caseClass.scala

abstract class A
case class A1(in: String) extends A
case class A2(num: Int) extends A
 
val test1: A = A1("Hello")
val test2: A = A2(1)
 


def receive (inObj: A) = {

    /* 
     * option 1:
     * Does not need "case" before "class" on lines 2 and 3
     */
    inObj match {
        case _: A1 => println("this")
        case _: A2 => println("that")
    }
     
    /*
     * option 2:
     * More of a functional programming approach
     */
    inObj match {
        case A1(string) => println(string)
        case A2(number) => println(number)
    }
}

receive(test2)