scala: Any default apply method in a class?

Does scala provide a default apply method for a class?

I have a class:

class Player(tea: String, sal: Int = 0) {
    val team  = tea
    private val salary = sal
}

So no apply method here, and I haven’t defined any companion object for it, so no apply method from there too.

But I am able to do:

val player = Player("AAAA", 1000)

With no ‘new’ operator used, I understand that this line of code must invoke some apply method. But there is none defined by me. So how does it work?

>Solution :

Yes, since Scala 3, as described in the docs:

Scala case classes generate apply methods, so that values of case classes can be created using simple function application, without needing to write new.

Scala 3 generalizes this scheme to all concrete classes. Example:

class StringBuilder(s: String):
  def this() = this("")

StringBuilder("abc")  // old: new StringBuilder("abc")
StringBuilder()       // old: new StringBuilder()

This works since a companion object with two apply methods is generated together with the class. The object looks like this:

object StringBuilder:
  inline def apply(s: String): StringBuilder = new StringBuilder(s)
  inline def apply(): StringBuilder = new StringBuilder()