Question

Suppose I have an array of strings in Scala:

val strings = Array[String]("1", "2", "3", "4", "5", "6", "7")

What I need is to make a new array which elements will be obtained as a concatenation of each three (any number) consequent elements of the first array, which should result in ("123", "456", "7")

Being new to Scala I wrote the following code which was neither concise nor effective:

var step = 3
val strings = Array[String]("1", "2", "3", "4", "5", "6", "7")
val newStrings = collection.mutable.ArrayBuffer.empty[String]

for (i <- 0 until strings.length by step) {
  var elem = ""
  for (k <- 0 until step if i + k < strings.length) {
    elem += strings(i + k)
  }
  newStrings += elem
}

What would be the Scala way for doing this?

Answer 1

strings.grouped(3).map(_.mkString).toArray

or

strings grouped 3 map (_.mkString) toArray

I personally prefer the first version 🙂