From: Brian Candler <B.Candler@...>
Date: 2003-07-19T05:25:14+09:00
Subject: Re: [SNIPPET] Binary counter

On Sat, Jul 19, 2003 at 04:36:23AM +0900, Mauricio Fern?ndez wrote:
> >> 8.times {|i| 4.times {|j| print i[3-j]}; puts }
> 0000
> 0001
> 0010
> 0011
> 0100
> 0101
> 0110
> 0111
> => 8

And also:

irb(main):003:0> 8.times { |i| puts "%04b" % i }
0000
0001
0010
0011
0100
0101
0110
0111
=> 8