extending case classes

While Scala case classes are best used to represent Data objects, it can be handy to extend their behavior beyond the standards set in the Scala language.

For example, a “composite getter”, #fullName that combines two constructor parameters, firstName and lastName:

trait Person {
  val firstName: String
  val lastName: String
  def fullName: String = s"$firstName $lastName"
}

case class Student(firstName: String, lastName: String) extends Person

val billy = Student("billy", "ocean")

billy.fullName
// res3: String = "billy ocean"