From: Chris Carter <cdcarter@...>
Date: 2007-02-25T06:19:44+09:00
Subject: Re: Just started learning Ruby

On 2/24/07, DracoJK <dracojk@gmail.com> wrote:
> I've been working through the Humble Ruby Book that I found in a signature
> of one of ruby talk's list members, and would like a little more explanation
> as to how pointing to a pointer works.
>
> The example used was a string:
>
> first_var = "i hold a reference"
> → i hold a reference
> second_var = first_var
> → i hold a reference
> second_var.chop! # Chops off the last character of the string
> → i hold a referenc
> first_var
> → i hold a referenc
>
> This works fine... I understand this... but I tried it with an integer
> rather than a string, and it doesn't seem to work how I expect it to.
>
> first_var = 1
> second_var = first_var
> second_var += 1
> puts first_var
>
> this outputs 1, but I thought it'd output 2... o_O
>
> What's the difference?  Why do variables work differently with integers as
> opposed to strings?
>
> Thanks for answering my ever so simple question. :)  I come from a java
> background and never really thought about how things work when you point a
> variable to another variable. :P
>
Because the += operator actually reassigns the object, so you are
doing something like
first_var = 1
second_var = first_var
hold = second_var + 1
second_var = hold

-- 
Chris Carter
concentrationstudios.com
brynmawrcs.com