I am currently trying to teach myself scala by rewriting projects from my intro CS class, which was taught in C++. In addition to just learning the syntax I am trying to gain understanding of how functional programming works and what is considered good functional programming style.

Below I've included both the original code, which is a simple while loop that continues looping until the user selects the 'quit' option, and my attempt at a functional equivalent. Have I done this correctly? What could be improved?

Original imperative version in C++:

int main()
{
  int option = -1;

  while (option != 3)
  {        
    cout << fixed;
    cout << "Please select one of the following:" << "\n1 - one" <<
      "\n2 - two" << "\n3 - quit" << endl;
    cin >> option;
    if (option == 1)
    {
      cout << "selected 1" << endl;
    }
    else if (option == 2)
    {
      cout << "selected 2" << endl;
    }
    else if (option == 3)
    {
      cout << "selected quit.\n";
    }
    else
    {
      cout << "Sorry, that command is not recognized. ";
    }
  }
  return 0;  
}

My attempt at a functional version in scala:

def menu(option: Int) {
  println("""|Please select one of the following:
             |  1 - one 
             |  2 - two
             |  3 - quit""".stripMargin)
  if (option == 1) {
    println("selected 1")
    val opt = StdIn.readInt
    menu(opt)
  }
  else if (option == 2) {
    println("selected 2")
    val opt = StdIn.readInt
    menu(opt)
  }
  else if (option == 3) {
    println("selected quit")
  }
  else {
    println("Sorry, that command is not recognized")
  }
}

def main(args: Array[String]) {
  println("""|Please select one of the following:
             |  1 - one 
             |  2 - two
             |  3 - quit""".stripMargin)
  val opt = StdIn.readInt
  menu(opt)
}