Scala ListBuffer data not accessible

I have the following code:

 val lines =  Source.fromFile("/home/cloudera/file_01").getLines().drop(1).toVector

I get a vector of file lines - which is file:

lines: Vector[String] = Vector(blk1|20170912|||||, ||||||, |c1|c2|c3|||, |201710|201711|201712|||, v1|1|4|9|||, v2|1||7|||, blk2||||||, ||||||, c4|c5|c6||||, |201710|201711|201712|||, h|h|h|h|h|h|h, j|j|j|j|j|j|j, k|k|k|k|k|k|k, m|m|m|m|m|m|m, ||||||, ||||||, ||||||, 201801|1|5||||, 201802|9|100||||, 201803|9|||||)

What i then want to do is to take each entry which is an Array of String and then put into an Array of Array of String.

I get, which is fine:

scala> val current_line_values_1 = lines(3).split("\\|", -1).map{x => val trimmed = x.trim; if (trimmed.isEmpty) "empty string" else trimmed}
current_line_values_1: Array[String] = Array(empty string, 201710, 201711, 201712, empty string, empty string, empty string)

scala> val current_line_values_2 = lines(3).split("\\|", -1).map{x => val trimmed = x.trim; if (trimmed.isEmpty) "empty string" else trimmed}
current_line_values_2: Array[String] = Array(empty string, 201710, 201711, 201712, empty string, empty string, empty string)

Done this way for simplicity in SBT Console.

So, I looked at ListBuffer, because I want to make a List of these 2 which are a subset of all the lines.

I did as per the mutable.ListBuffer using Alvin Alexander's example the following:

var fruits = new ListBuffer[String]()
//var fruits = new ListBuffer[Array[String]]()  - this made no difference either

fruits += current_line_values_1.toString
fruits += current_line_values_2.toString

I had to use toString to get it to compile.

I get the right number of elements, but printing out like this:

      saveLinesList1 = fruits.toList

      // How to print 2 dimensional?
      for (j <- 0 to (saveLinesList1.length - 1)) {

        println("hello " + saveLinesList1(j))
        val x = saveLinesList1(j)
           for (k <- 0 to (x.length - 1)) {
             println("hello 2 " + x(k))
           }

      } // End of for loop.

gives me:

hello [Ljava.lang.String;@51dd09f
hello 2 [
hello 2 L
hello 2 j
hello 2 a
hello 2 v
hello 2 a

What has happened to the content? Array of Array[String] did not help either. Looking at 2 dimensional array did not clear it up either.

All I need is an array of the lines which are array of String.

Solution

When you apply toString to an Array it will return back object not the String value. Instead try using mkString which concatenates each value inside Array and returns a single String value. Try using below code,

//no need to define it as var its already mutable
val fruits = new ListBuffer[String]()
fruits += current_line_values_1.mkString
fruits += current_line_values_2.mkString
//to print the ListBuffer
fruits.foreach(println(_))

If you need Array[String] instead of String you can use following,

val fruits = new ListBuffer[Array[String]]()
fruits += current_line_values_1
fruits += current_line_values_2