How to initial a 2 Dimensions matrix with independent number of rows and columns in Scala?

Question

I've seen something like:

def matInit(n:Int):Array[Array[Int]]={
          val maxval=5
          val rnd=new Random(100)

          Array.tabulate(n){_=>Array.tabulate(n){_=>rnd.nextInt(maxval+1)+1}}
        }

but in this template above, the way of initialization is complicated, and the number of rows and columns is equal. Is there an improved way based on it? Thanks.

Answer 1

Array.fill allows creating of 2D arrays and makes the logic a bit simpler.

def matInit(n: Int, m: Int): Array[Array[Int]] = {
  val maxval = 5
  val rnd = new Random(100)

  Array.fill(n, m)(rnd.nextInt(maxval + 1) + 1)
}

This works because fill takes a by name argument which means that the expression is evaluated for each element in the new Array rather than being calculated once and passed as a value.