From: "David A. Black" <dblack@...>
Date: 2007-08-21T01:24:14+09:00
Subject: Re: Assignment as a reference?

Hi --

On Tue, 21 Aug 2007, Morgan Grubb wrote:

> Hi,
>
> I ran into a simple issue earlier with assignment seeming to make
> references. I'm new to Ruby so perhaps this is how it's supposed to be. Here

It is.

> is an abridged version of what happened:
>
> foo = 'bar' #=> bar
> foo2 = foo #=> bar
> foo = foo.gsub 'bar', 'wibble' #=> wibble
> foo2 #=> bar
>
> foo = 'bar' #=> bar
> foo2 = foo #=> bar
> foo.gsub! 'bar', 'wibble' #=> wibble
> foo2 #=> wibble
>
> You can paste those straight into irb and get the same output. Could someone
> please explain why the second example changes foo2?

Ruby assignments pretty much traffic in references. When you do:

   foo2 = foo

you're giving foo2 a copy of the reference that foo contains. When you
change the object, you see the change reflected through any reference
to it.


David

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