On Nov 20, 2006, at 10:50 AM, Ross Bamford wrote:

> On Mon, 20 Nov 2006 15:33:33 -0000, David Lelong  
> <drlelon / yahoo.com> wrote:
>
>> Hi,
>>
>> I have a hash that contains the following keys/values:
>>
>> [#<Contact_List:0x2607150 @attributes={"contact_id"=>"4"}>,
>> #<Contact_List:0x2607114 @attributes={"contact_id"=>"8"}>]
>>
>> I want to create an array containing the contact_id values.   
>> What's an
>> easy way to do this?
>>
>> Thanks,
>>
>> David
>>
>
> Assuming Contact_List (aside: why an underscored class name?) has  
> an attr_accessor for 'attributes', you might try:
>
> 	a.map { |clist| clist.attributes['contact_id'] }
>
> (where 'a' is the array you show above).
>
> -- 
> Ross Bamford - rosco / roscopeco.remove.co.uk

Well, the OP asked for easy and what's easier than Symbol#to_proc   
(or am I reading Rails and ActiveRecord into this question where it's  
missing?)

a = [#<Contact_List:0x2607150 @attributes={"contact_id"=>"4"}>,
#<Contact_List:0x2607114 @attributes={"contact_id"=>"8"}>]

a.map(&:contact_id)
=> [4, 8]

-Rob

Rob Biedenharn		http://agileconsultingllc.com
Rob / AgileConsultingLLC.com