Rails - Jun 2009 - How to add up an array's element with a rails way?

Hi,

I have a method like this, calculating the sub_total in an order model:

def sub_total
  result = 0
  for item in self.order_items
    result += item.price
  end
  result
end

Is there a rails way to make the method more simple and concise?

Thank you :)

-- 
regards,
Kai Fu

Material Science and Engineering
Huazhong University of Science and Technology
Wuhan Hubei Province P.R.China
E-mail: corntrace-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org

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On Jun 5, 5:01 am, Kevin Fu
<corntr...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:
> Hi,
>
> I have a method like this, calculating the sub_total in an order model:
>
> def sub_total
>   result = 0
>   for item in self.order_items
>     result += item.price
>   end
>   result
> end
>
> Is there a rails way to make the method more simple and concise?
>
Have a peak at the sum method :-)

Fred
> Thank you :)
>
> --
> regards,
> Kai Fu
>
> Material Science and Engineering
> Huazhong University of Science and Technology
> Wuhan Hubei Province P.R.China
> E-mail: corntr...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org

use active record sum method

self.order_items.sum( :price )

-Sandip

On Fri, Jun 5, 2009 at 12:50 PM, Frederick Cheung <
frederick.cheung-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
>
>
>
> On Jun 5, 5:01 am, Kevin Fu
<corntr...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> > Hi,
> >
> > I have a method like this, calculating the sub_total in an order
model:
> >
> > def sub_total
> >   result = 0
> >   for item in self.order_items
> >     result += item.price
> >   end
> >   result
> > end
> >
> > Is there a rails way to make the method more simple and concise?
> >
>
> Have a peak at the sum method :-)
>
> Fred
> > Thank you :)
> >
> > --
> > regards,
> > Kai Fu
> >
> > Material Science and Engineering
> > Huazhong University of Science and Technology
> > Wuhan Hubei Province P.R.China
> > E-mail: corntr...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org
> >
>

-- 
Ruby on Rails Developer
http://sandip.sosblog.com
http://funonrails.wordpress.com
www.joshsoftware.com

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