From: Robert Dober <robert.dober@...>
Date: 2007-08-14T18:11:04+09:00
Subject: Re: Symbols and strings

On 8/14/07, maghac <magnus.hacker@gmail.com> wrote:
> Hi,
> as a long-term perl user just recently converted to ruby, I'm curious
> about one particular syntax "feature": ruby symbols and how they
> relate to strings.
>
> Isn't really :name a shortcut for "name"? (I read somewhere in an
> explanation of attr_reader that e.g :age was the "name" of the
> variable age, while age is the actual content of that variable). If
> so, couldn't you use this in hash keys as well, e.g say hashvar[:key]
> instead of hashvar['key'].
>
> Are there situations where you cannot use symbols instead of strings,
> or the other way around?
>
> I might be too used to the way strings and barewords are handled in
> perl (if something looks like a string, and it's not a function call,
> it's interpreted as a string. This means you can say $hashvar{key}
> without quoting the key).
This question is asked very frequently, please search the archives for
more info.
I will try to give a very quick answer nevertheless:

Symbols are immutable, thus great to represent immutable data, often
that makes them an excellent choice for hash keys
{ :the_value => 42, :alternatively => 22, :or_even => 101010 }
they just do not play the role of Strings, coming from Perl you just
had to use Strings, you did not have a tool for names (wait a moment
was there not such a thing as references to constants?).
Very roughly put I see Symbols as name, and Strings as data, whenever
I can use Symbols I use them, comes natural after some time.

HTH
Robert
-- 
[...] as simple as possible, but no simpler.
-- Attributed to Albert Einstein