scala feature for filtering lists explained

scala> val list1 = List(false,true,true,true) list1: List[Boolean] = List(false, true, true, true)

scala> val list2 = List(1,0,1,1) list2: List[Int] = List(1, 0, 1, 1)

scala> val addr = (list1 zip list2).filter(_._1).map(_._2) addr: List[Int] = List(0, 1, 1)