RosettaCodeData/Task/Identity-matrix/Vala/identity-matrix.vala

int main (string[] args) {
   if (args.length < 2) {
      print ("Please, input an integer > 0.\n");
      return 0;
   }
   var n = int.parse (args[1]);
   if (n <= 0) {
      print ("Please, input an integer > 0.\n");
      return 0;
   }
   int[,] array = new int[n, n];
   for (var i = 0; i < n; i ++) {
      for (var j = 0; j < n; j ++) {
         if (i == j) array[i,j] = 1;
         else array[i,j] = 0;
      }
   }
   for (var i = 0; i < n; i ++) {
      for (var j = 0; j < n; j ++) {
         print ("%d ", array[i,j]);
      }
      print ("\b\n");
   }
   return 0;
}