From: Robert Klemme <shortcutter@...>
Date: 2008-03-06T23:43:25+09:00
Subject: Re: Ruby Basics / define met;hod

2008/3/6, Chinna Karuppan <chinnakaruppan@gmail.com>:
>  I am new to Ruby and This is a very basic question.when I type p self in
>  irb it gives me 'main'.

Correct.

>  when I say class what is happening in the backend.since within a class
>  end I am able to call define_method which is a private method and should
>  never be available to anybody and another intersting thing is it is not
>  accessible outside of the  class.

irb(main):001:0> class Foo
irb(main):002:1> p [self,self.class]
irb(main):003:1> end
[Foo, Class]
=> nil
irb(main):004:0>

Inside a class body /self/ is the class instance being defined right now.

>  so my question is how is a private method accessible outside
>  what is happening when a class is defined.

First of all, inside "class...end" you are not "outside".

Second, if you want to access any private method you can do so via send:

irb(main):004:0> class Foo
irb(main):005:1> private
irb(main):006:1> def bar()123 end
irb(main):007:1> end
=> nil
irb(main):008:0> Foo.new.bar
NoMethodError: private method `bar' called for #<Foo:0x7ff82440>
        from (irb):8
        from :0
irb(main):009:0> Foo.new.send :bar
=> 123

> it is of type Class
>  automatically...I don't quite get it.
>  As soon as you start IRB a main object is created which is of type
>  Object.is it is  right statement...

I do not know what you mean by your last sentence.  "main" is of type
Object - but it has some methods added:

$ irb
irb(main):001:0> puts class<<self;self;end.instance_methods(false).sort
bindings
cb
chws
conf
context
cws
cwws
exit
fg
help
include
install_alias_method
irb
irb_bindings
irb_cb
irb_change_binding
irb_change_workspace
irb_chws
irb_context
irb_current_working_binding
irb_current_working_workspace
irb_cwb
irb_cws
irb_cwws
irb_exit
irb_fg
irb_help
irb_jobs
irb_kill
irb_load
irb_pop_binding
irb_pop_workspace
irb_popb
irb_popws
irb_print_working_binding
irb_print_working_workspace
irb_push_binding
irb_push_workspace
irb_pushb
irb_pushws
irb_pwb
irb_pwws
irb_quit
irb_require
irb_source
irb_workspaces
jobs
kill
popb
popws
private
public
pushb
pushws
pwws
quit
source
to_s
workspaces
=> nil
irb(main):002:0>

Kind regards

robert

-- 
use.inject do |as, often| as.you_can - without end