Question

For example I’d like to have this to work the way to set jDName to “John Doe” and jDAge to 32:

case class Person(name : String, surname : String, age : Int)

val johnDoe = Person("John", "Doe", 32)

val jDName : String = johnDoe

val jDAge : Int = johnDoe

Can I write functions in the Person class to provide implicit conversion to String, Int and other (custom) types? And another thing is for explicit cast operation – also interesting, but I don’t know exactly how should I write this for an example in Scala.

Answer 1

Sure, put them in the companion object.

scala> case class Person(name : String, surname : String, age : Int); object Person {
     |   implicit def pToString(p: Person) = p.name + " " + p.surname + ", age " + p.age
     |   implicit def pToInt(p: Person) = p.age
     | }
defined class Person
defined module Person

scala> val johnDoe = Person("John", "Doe", 32)
johnDoe: Person = Person(John,Doe,32)

scala> val jDName : String = johnDoe
jDName: String = John Doe, age 32

scala> val jDAge : Int = johnDoe
jDAge: Int = 32