From: george.marrows@... (George Marrows)
Date: 2004-06-22T17:23:19+09:00
Subject: Re: A question about Class and Object

"Sam Sungshik Kong" <ssk@chol.nospam.net> wrote

> I'm using Ruby 1.8.
> 
> Object.class.methods.length #->74
> Object.methods.length #->73
> 
> Object.class is Class.
> Object is type of Class.
> 
> I'm still confused with class and object and metaclass...

Hi Sam --

The key is that what class an object is doesn't say everything about
what methods it has, because of the existence of singleton methods.
[And the list of methods an object has doesn't say everything about
what messages it responds to, because of the existence of
method_missing - though this is irrelevant to your question :)] James
Britt's recent message http://www.ruby-talk.org/104273 explains this,
though without mentioning singleton methods explicitly.

In this case, the additional method ("nesting") is sneaking in as
singleton method on Module:

irb(main):015:0> Module.singleton_methods
=> ["constants", "nesting"]

constants is also a Module singleton method, but nesting is the only
new one:

irb(main):016:0> Object.methods.include?("nesting")
=> false
irb(main):017:0> Object.methods.include?("constants")
=> true

... hence the difference of 1 in the number of methods that Object and
Module have.

Hope this helps,

George.