Initializing a 2D (multi-dimensional) array in Scala

Question

It\'s easy to initialize a 2D array (or, in fact, any multidimensional array) in Java by putting something like that:

int[][] x = new int[][] {
        { 3,          


        

Answer 1

Since I'm also in disgust with this trailing comma issue (i.e. I cannot simply exchange the last line with any other) I sometimes use either a fluent API or the constructor syntax trick to get the syntax I like. An example using the constructor syntax would be:

trait Matrix {
  // ... and the beast
  private val buffer = ArrayBuffer[Array[Int]]()
  def >(vals: Int*) = buffer += vals.toArray
  def build: Array[Array[Int]] = buffer.toArray
}

Which allows:

// beauty ... 
val m = new Matrix {
  >(1, 2, 3)
  >(4, 5, 6)
  >(7, 8, 9)
} build

Unfortunately, this relies on mutable data although it is only used temporarily during the construction. In cases where I want maximal beauty for the construction syntax I would prefer this solution.

In case build is too long/verbose you might want to replace it by an empty apply function.