Scala case classes

A case class is a simplified type that can be used without calling new Classname(..). For example, we could have this script that defines a case class and uses it:

case class Car(brand: String, model: String) 
val buickLeSabre = Car("Buick", "LeSabre") 

So, we have a case class called Car. We make an instance of that class called buickLeSabre.

The case classes are most useful for pattern matching, since we can easily construct complex objects and examine their content. For example:

def carType(car: Car) = car match { 
  case Car("Honda", "Accord") => "sedan" 
  case Car("GM", "Denali") => "suv" 
  case Car("Mercedes", "300") => "luxury" 
  case Car("Buick", "LeSabre") => "sedan" 
  case _ => "Car: is of unknown type" 
} 
val typeOfBuick = carType(buickLeSabre) 

 

We define a pattern match block (as in the previous section of this chapter). In the match block, we look at a Car object that has brand as GM and model as Denali, and so forth. For each of the models...