Different behavior when declaration type is different(Set vs TreeSet)

Question

    var set = TreeSet(5,4,3,2,1)
    println(set)

    val diffSet: TreeSet[Int] = set
    // if I change above code to val diffSet: Set[Int] = set
    // the result is          


        

Answer 1

You can do:

scala> for (i <-genSet.view; x = i + 1) println(x)
2
3
4
5
6

Although, it's the type of trick that when you look at it after a few months, you may wonder why you added .view ...