From: Fergal J Byrne <editor@...>
Date: 2007-03-16T00:47:59+09:00
Subject: Re: freeze string fails to freeze ???

jwaala.amplify@gmail.com wrote:
>>> a='asdf'
> => "asdf"
>>> a.freeze
> => "asdf"
>>> a='qwer'
> => "qwer"
> 
> should'nt that throw and exception ???
> 

freeze is a method on the object referenced by a,
not on the variable a (a is just a name, not the
object itself).

a = 'abcd'
a.freeze

# a[2]='w' raises
# ./freezetest.rb:7:in `[]=': can't modify frozen string (TypeError)

This causes an exception because you are trying to modify the
frozen object.

a = 'defg'

This does not, because the object (which up to now was
referenced by a) is not changed.  a now refers to a
different object.

Try it with a constant:

A = 'abcd'
A = 'defg' # raises a warning: already initialized constant A



-- 

Regards,

Fergal Byrne - Technical Director


Adnet: Web Builders to the Design Industry

http://www.adnet.ie/  t:+353 1 855 8951 aim/skype:FergByrne

=== We've Moved! 63 Lower Gardiner Street, Dublin 1 ===