From: "T. Onoma" <transami@...>
Date: 2003-12-07T20:14:01+09:00
Subject: Re: newbie question

On Sunday 07 December 2003 10:41 am, nainar wrote:
>  In C, parameters are  passed by value , unless pointers to variables are
> used .
>
>  In Perl, params are passed in the '@_' array and contains references to
> the original variables and assignments to the elements of @_ are reflected 
> in the original vars(Execept when the whole '@_' is assigned to at once ).
>
>  How does it work in Ruby?. I couldn't find anything on this in docs.

I find it confusing sometimes myself too, but it does "pan out" when you think 
about how ruby works:

 ��def f2(b)
�  ��b[0]=[9,8,7]
���end

In this case b references the passed variable like a c pointer, so assignment 
to one of its elements effects the original.

  �def f1(a)
  �� a=[9,8,7]
���end

In this case you have "dettached" the original reference to a, giving it a new 
one, so the original is unaffected. Try this instead:

  �def f1(a)
  �� a.replace [9,8,7]
���end

This all has to do with what = does --it assigns reference, and is not an 
inplace assignment.

T.