From: Rajinder Yadav <devguy.ca@...>
Date: 2009-12-14T18:19:31+09:00
Subject: Re: about object methods

Ruby Newbee wrote:
> Hello,
> 
> I have two questions,
> 
> 1. what's the difference between class method and module method?

a class method well belongs to the class =P
there can only be one class method, you don't need to create an 
object(instance) to call a class method

a module method is a way to package methods using namespacing,
a module is not a like a class, you can create instance of a class but 
not a module

more on modules:
http://www.ruby-doc.org/docs/ProgrammingRuby/



> 2. when I say: Dir.pwd, is this a class method or a module method? How
> to know if Dir is a module or a class?
> 

use ri to display class information, it clearly states 'pwd' is a class 
method,
type 'ri Dir' at the prompt,
type 'ri' alone to find out how to use it


yadav@KubuntuX64:$ ri Dir

------------------------------------------------------------- Class: Dir
      Objects of class +Dir+ are directory streams representing
      directories in the underlying file system. They provide a variety
      of ways to list directories and their contents. See also +File+.

.....
.....
(edit)
......
......

Class methods:
--------------
      [], chdir, chroot, delete, entries, foreach, getwd, glob, mkdir,
      mktmpdir, new, open, pwd, rmdir, tmpdir, unlink


> 
> Thanks.
> 
> 

-- 
Kind Regards,
Rajinder Yadav

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