From: Pat Maddox <pergesu@...>
Date: 2006-05-16T18:14:52+09:00
Subject: Re: learn to program

On 5/16/06, Tim Becker <a2800276@gmail.com> wrote:
> > wuss_var is "" after major_pest returns.  So apparently you can affect
> > it.  The only way (that I know of) to write that method without
> > affecting the outside variable is
> >
> > def major_pest(wussy_var)
> >   guardian_angel = wussy_var.clone
> >   guardian_angel.slice!(0..-1)
> >   puts "HAHA! I ruined your variable!"
> > end
>
> the reason that ruins your variable is that `slice!` modifies the
> object in place (this is why it ends in an `!`).

I understand that...what I don't necessarily understand is why
wuss_var is "" outside of the method.  If they really have no
interaction, then I wouldn't expect it to change.


If you do:
>
> > def major_pest(wussy_var)
> >   wussy_var=wussy_var.slice(0..-1)
> >   puts "HAHA! I ruined your variable!"
> > end
>
> instead you don't change the original object, instead slice creates
> the clone for you.

My real issue is with the excerpt from the book, which would make new
programmers think they can do whatever they want to an object inside a
method and not have it affect anything outside of it.  Clearly that is
not the case.

Pat