newby question

[Alfonso]

Sorry for the too elemental question (don't know if this is the right
place to make questions like this) I just have started with ruby, and
don't understand the difference "::" "." I have read that :: is for
accessing constants, but then I see, that, for example, I can make a new
object like with ::new or .new. Could anyone explain that?

Thank you very much.


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[Patrick Hurley]

Sorry for the too elemental question (don't know if this is the right
place to make questions like this) I just have started with ruby, and
don't understand the difference "::" "." I have read that :: is for
accessing constants, but then I see, that, for example, I can make a new
object like with ::new or .new. Could anyone explain that?

There is some overlap, but in general usage, use :: to access names
that are scoped within modules and use . to send messages (call)
methods.

At least while you are getting started, this is the easiest thing to remember.
pth

 

[David Vallner]

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=20
There is some overlap, but in general usage, use :: to access names
that are scoped within modules and use . to send messages (call)
methods.
=20

To be precise, :: and . are completely equivalent operators to call
methods of an object. I think (not really sure) that an older version of
Ruby only let you use :: for class methods, but that's no longer the case=
=2E

Only :: can be used for constant lookup; it's idiomatic to use . for any
method calls, as Patrick says.

David Vallner


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[Alfonso]

Thank you very much for your answers. So if I have understood right:

- "::" constants, and module methods
- "." methods

I also have read today in "ruby in a nutshell", that "::" is preferred
also with class methods (but the war wroten in 2001, so it could be a
bit outdated).


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LLama Gratis a cualquier PC del Mundo.
Llamadas a fijos y móviles desde 1 céntimo por minuto.
http://es.voice.yahoo.com

 

[dblack]

Hi --

Thank you very much for your answers. So if I have understood right:

- "::" constants, and module methods
- "." methods

I also have read today in "ruby in a nutshell", that "::" is preferred also
with class methods (but the war wroten in 2001, so it could be a bit
outdated).

My recommendation is:

"::" for constant paths
"." for method calls

I don't think there's any reason to use :: for method calls just
because the receiver is a class or module. It just adds an
unnecessary special case.


David

--
David A. Black | (e-mail address removed)
Author of "Ruby for Rails" [1] | Ruby/Rails training & consultancy [3]
DABlog (DAB's Weblog) [2] | Co-director, Ruby Central, Inc. [4]
[1] http://www.manning.com/black | [3] http://www.rubypowerandlight.com
[2] http://dablog.rubypal.com | [4] http://www.rubycentral.org