In Scala, how do you define a local parameter in the primary constructor of a class?

Question

In Scala, how does one define a local parameter in the primary constructor of a class that is not a data member and that, for example, serves only to initialize a data membe

Answer 1

Derek,

If you have this:

class A(a: Int) {
  val aa = a // reference to constructor argument in constructor code (no problem)
  def m: Float = a.toFloat // reference to constructor argument in method body (causes a to be held in a field)
}

you'll find (using javap, e.g.) that a field named "a" is present in the class. If you comment out the "def m" you'll then see that the field is not created.