From: bbiker <renard@...>
Date: 2006-07-09T00:15:06+09:00
Subject: Re: storing and using references to variables

Russell Fulton wrote:
> Hi,
>    I want to store a reference to a scalar variable (in perl parlance)
> in another variable and then assign a value to the stored variable.  I
> have done this for contiainers by simply assigning the container to the
> variable:
>
>  ref = a = []
>
> ref[0] = 'x'
>
> leaves a[0] == 'x'
>
> as it should.
>
> I want to be able to do something similar but using a simple variable
> instead of an array. E.g. in perl
>
> $ref = \$a
>
> $$ref = 'x'
>
> but I can not find anything about explicitly dereferencing a variable.
>
> what I have done in the mean time is to use an array and only use the
> first element.
>

In Ruby, all variables (except for number objects) are references and
there is no need to implicitly derefence.

now all methods that do not involve an assignment on one will be
reflected  will be reflected on the other

Try the following in irb

astring = "this is a string object"
bstring = astring

or

bstring = astring = ""  or bstring = astring = String.new
astring << "this is a string object"

astring.object_id
bstring.object_id        will show that both variables point to the
same object

now all methods invoked that do not involve an assignment on one will
be reflected  on the other

for example:

bstring.capitalize!    # both bstring and astring are identical

if you
bstring = "this is a new string object"
bstring.object_id       shows that bstring points to a different object
and astring and bstring are no longer the same


the same would have happened if you ref = [ 1, 2, 3 ]  now ref and a
are different objects