Question

I have the following two lists , I am not sure if at run time list2 will be empty or full , but list1 will be always non empty, how to ensure that for the following for loop value of list are at least printed

val list1 = List(1,2,3)                   //> list1  : List[Int] = List(1, 2, 3)
val list2 = List()                        //> list2  : List[Nothing] = List()
for( counti <- list1 ; countj <- list2 ) yield println (counti + " - " + countj)
                                                  //> res7: List[Unit] = List()

I am expecting something like

1 - BLANK
2 - BLANK
3 - BLANK

but above for loop is giving me blank results List()

Answer 1

for (
  counti <- list1;
  countj <- if(list2.nonEmpty) list2 else List("BLANK")
) {
  println(counti + " - " + countj)
}