From: Walter Szewelanczyk <walter@...>
Date: 2004-08-14T05:26:20+09:00
Subject: Re: Question: A method for summing several variables

Harry Truax wrote:

> Lennon,
> 
> Thanks for the quick reply. Unfortunately, I am required to use the box
> variables (box1_1, box12_24,...etc.).
> 
> Harry

Its not very pretty and it can be optimized quite a bit, but the concept 
might work for you.

$SAFE=3

class SomeClass
   attr_accessor :box1_1, :box1_2, :box1_3, :box1_4, :box1_5
   attr_accessor :box2_1, :box2_2
   attr_accessor :box3_1, :box3_2

   def initialize
     @box1_1 = 1
     @box1_2 = 2
     @box1_3 = ""
     @box1_4 = 4
     @box1_5 = ""

     @box2_1 = ""
     @box2_2 = ""

     @box3_1 = 100
     @box3_2 = 200
   end

   #pass in a string for the box you want
   def sum(box)
     find_box_variables(box).inject(0){|sum, var| sum+send(var).to_i}
   end

   def find_box_variables(box)
     public_methods.find_all{|var_name| /^#{box}_\d+$/ =~ var_name}
   end
end

s = SomeClass.new
puts s.sum("box1")
puts s.sum("box2")
puts s.sum("box3")

-------------- OUTPUTS -------------------------

7
0
300


Hope that helps,

Walt

-- 
Walter Szewelanczyk
IS Director
M.W. Sewall & CO.        email : walter@mwsewall.com
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