如何打印另一个列表中的列表？ （阶）

Question

我有以下代码：

var sessionIds = List[Int](12345,54321)
var Frames = List[(String, String, String, String)](("Music","Duration","Distance","Whatever"))
var someMoreFrames = List[(Int, Int, String)](1,2,"hello"))

  //Do some other stuff here

var returnValue = List[(List[Int], List[(String, String, String, String)], List[(Int, Int, String)])]((sessionIds,Frames,someMoreFrames))

现在我要打印列表returnValue，我想要以下输出：

12345
54321
(Music,Duration,Distance,Whatever)
(1,2,hello)

Answer 1

对于您想要的打印，您可以尝试：

returnValue.foreach { x =>
  println(x._1.foreach(println) + "\n" +
    x._2.foreach(println)+ "\n" +
    x._3.foreach(println))
}

它会根据您的需要提供输出：

12345
54321
(Music,Duration,Distance,Whatever)
(1,2,hello)

Answer 2

这应该可以解决问题：

var sessionIds = List[Int](12345,54321)
var Frames = List[(String, String, String, String)](("Music","Duration","Distance","Whatever"))
var someMoreFrames = List[(Int, Int, String)]((1,2,"hello"))

val returnValue = sessionIds ++ Frames ++ someMoreFrames
returnValue.foreach(line => println(line))