From: James Edward Gray II <james@...>
Date: 2006-01-05T04:07:52+09:00
Subject: Re: Question on iterating a hash

On Jan 4, 2006, at 12:46 PM, phil swenson wrote:

> I have a hash that looks like this : {"1"=>"0, "3"="1", "45"=>"1",
> "101"=>"0"}
>
> What I want is an array of all the keys that have hash values equal to
> "1" ["3","45"] in this case.
>
> Yeah, i can just iterate the keys... but it seems like there is a  
> "ruby"
> way to do this.  Any thoughts?

 >> h = Hash[*%w{1 0 3 1 45 1 101 0}]
=> {"45"=>"1", "1"=>"0", "101"=>"0", "3"=>"1"}
 >> h.select { |key, value| value == "1" }.map { |key, value| key }
=> ["45", "3"]

Hope that helps.

James Edward Gray II