From: "Marcel Molina Jr." <marcel@...>
Date: 2005-11-23T07:42:35+09:00
Subject: Re: How convert an integer to a bit array

On Wed, Nov 23, 2005 at 07:37:25AM +0900, Daniel Sch?le wrote:
> Curt Hibbs wrote:
> >Does anyone have a clever way to convert an integer to an array of bit
> >values?
> >
> >For example (using 8 bit integers):
> >
> >0 => [0, 0, 0, 0, 0, 0, 0, 0]
> >1 => [0, 0, 0, 0, 0, 0, 0, 1]
> >2 => [0, 0, 0, 0, 0, 0, 1, 0]
> >7 => [0, 0, 0, 0, 0, 1, 1, 1]
> >etc.
> >
> >I was looking at Array#pack and Array#unpack to do this, but haven't 
> >figured
> >it out yet. It just seems like there ought to be a simple way to do this.
> >
> >Anybody got a clever idea?
> >
> >Curt
> 
> irb(main):082:0> x = 7.to_s(2).split(//).map! {|bit| bit.to_i}
> => [1, 1, 1]
> irb(main):083:0> x.unshift(0) until x.length == 8
> 
> if your number always fit into 8 bit
> otherwise this doesn't work

You could do this:

x.unshift(0) until (x.size % 8).zero?

marcel
-- 
Marcel Molina Jr. <marcel@vernix.org>