From: Ian Macdonald <ian@...>
Date: 2002-10-22T12:03:21+09:00
Subject: Re: Things That Newcomers to Ruby Should Know (10/16/02)

On Sat 19 Oct 2002 at 00:42:20 +0900, Kontra, Gergely wrote:

> >   13. Ruby variables hold references to objects and the = operator
> >       copies the references. Also, a self assignment such as a += b is
> >       actually translated to a = a + b. Therefore it may be advisable to
> >       be aware whether in a certain operation you are actually creating
> >       a new object or modifying an existing one.
> 
> >    a. In Ruby the "self assignment operator" goes beyond "+=, -=, *=,
> >       /=, %=". In particular, operators such as "||=" also exist (but
> >       currently not for a class variable if it is not yet defined; this
> >       may change in the future). Please see Table 18.4 in the
> >       "Programming Ruby" book for the complete list.
> 
> Also notice (performance tip), that
> string << "another" is much faster than string+="another" (no extra
> object creation)
> so you should use any class-defined update-method, if exists.

Hmm, why does 'string += another' need to create a new object? string
already exists, so wouldn't the reference simply be updated?

Ian
-- 
Ian Macdonald               | Q: What do you call a monk who has had a
ian@caliban.org             | sex change operation? A: A transsister. 
                            | 
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