2darraymadness.rb

a = Array.new(9) { Array.new(9) { rand(0..9) } }
s = t = 0
(0...9).each do |i|
  (0...9).each do |j|
    print "#{a[i][j]} "
    s += 1
    if s == 3
      print ' | '
      s = 0
    end
  end
  puts
  t += 1
  if t == 3
    # each number and spaces + each delimiter and spaces
    puts '-' * ((2 * 9) + (3 * 3))
    t = 0
  end
end

2.times { puts }

(0...9).step(3) do |i|
  (0...9).step(3) do |j|
    (0...3).each do |y|
      (0...3).each do |x|
        print a[i + y][j + x].to_s + ' '
      end
      puts
    end
    puts
  end
end

6 6 5 | 3 3 7 | 6 6 9 |
5 9 3 | 0 9 4 | 0 0 0 |
6 7 9 | 6 9 9 | 8 5 2 |

5 1 5 | 2 6 0 | 9 5 4 |
1 7 5 | 2 8 6 | 2 9 1 |
5 8 9 | 8 3 0 | 3 0 5 |

4 5 7 | 6 3 3 | 2 9 4 |
3 0 4 | 1 9 1 | 3 1 4 |
4 3 1 | 4 0 2 | 5 7 6 |

6 6 5
5 9 3
6 7 9

3 3 7
0 9 4
6 9 9

6 6 9
0 0 0
8 5 2

5 1 5
1 7 5
5 8 9

2 6 0
2 8 6
8 3 0

9 5 4
2 9 1
3 0 5

4 5 7
3 0 4
4 3 1

6 3 3
1 9 1
4 0 2

2 9 4
3 1 4
5 7 6