From: "Daniel Schüle" <uval@...>
Date: 2005-11-23T07:37:25+09:00
Subject: Re: How convert an integer to a bit array

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

Regards, Daniel