initialising a 2-dim Array in Scala
- by Stefan W.
(Scala 2.7.7:) I don't get used to 2d-Arrays. Arrays are mutable, but how do I specify a 2d-Array which is - let's say of size 3x4. The dimension (2D) is fixed, but the size per dimension shall be initializable. I tried this:
class Field (val rows: Int, val cols: Int, sc: java.util.Scanner) {
var field = new Array [Char](rows)(cols)
for (r <- (1 to rows)) {
val line = sc.nextLine ()
val spl = line.split (" ")
field (r) = spl.map (_.charAt (0))
}
def put (val rows: Int, val cols: Int, c: Char) =
todo ()
}
I get this error:
:11: error: value update is not a member of Char
field (r) = spl.map (_.charAt (0))
If it would be Java, it would be much more code, but I would know how to do it, so I show what I mean:
public class Field
{
private char[][] field;
public Field (int rows, int cols, java.util.Scanner sc)
{
field = new char [rows][cols];
for (int r = 0; r < rows; ++r)
{
String line = sc.nextLine ();
String[] spl = line.split (" ");
for (int c = 0; c < cols; ++c)
field [r][c] = spl[c].charAt (0);
}
}
public static void main (String args[])
{
new Field (3, 4, new java.util.Scanner ("fraese.fld"));
}
}
and fraese.fld would look, for example, like that:
M M M
M . M
I get some steps wide with
val field = new Array Array [Char]
but how would I then implement 'put'? Or is there a better way to implement the 2D-Array. Yes, I could use a one-dim-Array, and work with
put (y, x, c) = field (y * width + x) = c
but I would prefer a notation which looks more 2d-ish.
