From: Todd Benson <caduceass@...>
Date: 2007-07-26T02:54:17+09:00
Subject: Re: Question - Passing parameters by reference

On 7/25/07, caof2005 <caof2005@gmail.com> wrote:
> Hello Folks
>
> My question is the following:
>
> How can I pass a reference to a method as an argument, so after
> finishing the execution of the method the argument gets updated with a
> new value. ( known as "pass by reference" in other languages ).
>
> example:
> ....
> def changeValue( val, cad )
>      temp = 0;
>      val = (val * 10) / cad.to_i
>      temp = cad.to_i + 3.to_i
>      cad = temp.to_s
> end
> ....
> ....
> val = 35;
> cad = "7"
>
> puts "val before calling changeValue:= " + val.to_s
> puts "cad before calling changeValue:=" + cad
>
> changeValue( val, cad )
>
> puts "val before calling changeValue:= " + val.to_s     #--- I pretend
> to print '50'
> puts "cad before calling changeValue:=" + cad          #--- I pretend
> to print '10'
>
> Regards
> Carlos

Assignment inside method scope is allowed, but creates a different
object.  What you get back from a method is what the method returns.
So you could mimic your desired behavior with...

def f(a, b)
  return a*10.0/b.to_i, (b.to_i+3).to_s
end

x, y = 35, "7"
x, y = f( x, y ) #this will make x equal to 50 and y equal to the string "10"

Does that make sense?

Todd