gmane.comp.lang.ruby.rails

Ro Ma | 23 Jul 06:22

Extracting one column from an array of objects


This seems really simple but I can't seem to find an answer.

Say I have an array of Users which has a column called 'id'. I need an
array that holds just the ids. Right now I'm doing:

for user in users
  ids << user.id
end

Is there a method to do this? Note that these objects aren't from my
database so I can't use find.
--

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giorgio | 23 Jul 06:52

Re: Extracting one column from an array of objects


You should be able to use ids= users.collect {|u| u.id}

G.
On Jul 23, 4:24 pm, Ro Ma <rails-mailing-l...@...> wrote:
> This seems really simple but I can't seem to find an answer.
>
> Say I have an array of Users which has a column called 'id'. I need an
> array that holds just the ids. Right now I'm doing:
>
> for user in users
>   ids << user.id
> end
>
> Is there a method to do this? Note that these objects aren't from my
> database so I can't use find.
> --
> Posted viahttp://www.ruby-forum.com/.
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Danny Burkes | 23 Jul 07:34

Re: Extracting one column from an array of objects


> Say I have an array of Users which has a column called 'id'. I need an
> array that holds just the ids. 

ids = users.collect(&:id)
--

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Samuel Flores | 23 Jul 18:00

Re: Extracting one column from an array of objects


users.map { |user| user.id }

Samuel Flores

Em 23/07/2008, às 01:24, Ro Ma <rails-mailing-list@...>  
escreveu:
!#x000a
>
> This seems really simple but I can't seem to find an answer.
>
> Say I have an array of Users which has a column called 'id'. I need an
> array that holds just the ids. Right now I'm doing:
>
> for user in users
>  ids << user.id
> end
>
> Is there a method to do this? Note that these objects aren't from my
> database so I can't use find.
> -- 
> Posted via http://www.ruby-forum.com/.
>
> >

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