From: Joel VanderWerf <vjoel@...>
Date: 2007-03-26T14:03:45+09:00
Subject: Re: how to tranlsate number to binary?

Phrogz wrote:
> On Mar 25, 10:06 pm, Joel VanderWerf <v...@path.berkeley.edu> wrote:
>> Ak 756 wrote:
>>> I want my function to give output 100100000011 for input 903. Where
>>> '1001','0000','0011' is the binary value for 9,0,3
>>> Is there efficient way to do this?
>> "903".split("").map{|s| "%04b" % s.to_i}.join
>> => "100100000011"
> 
> No need to call to_i on the digit strings:
> 
> irb(main):002:0> 903.to_s.split('').map{|n| "%04b" % n }.to_s
> => "100100000011"

Had no idea that would work, but now it seems obvious.... Apparently 
#Integer is being called by #% when the format char is 'b', because it 
works correctly with different bases:

"%04b" % "16"
=> "10000"
"%04b" % "0x10"
=> "10000"
"%04b" % "0b10000"
=> "10000"

-- 
       vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407