From: Daniel Tse <daniel@...>
Date: 2005-09-28T15:12:13+09:00
Subject: Re: class variables

v.nainar wrote:

>Hello!
>
>	What is wrong with the following code? Why is  @@id  incremented before 
>and not after the assignment? .  ( Sorry  if this sounds silly and I have
>overlooked something obvious )
>
>	
>#!/usr/local/bin/ruby
>class Foo
>  @@id=1
>  def initialize(s)
>    @s=s
>    @id=setId()
>  end
>  
>
You are assigning to the return value of setId, which is the incremented 
@@id: in Ruby, the implicit return value of a function is that of the 
last evaluated expression.

>  def setId()
>    @id=@@id
>    @@id+=1
>  end
>end
>
>foo1=Foo.new("one")
>foo2=Foo.new("two")
>foo3=Foo.new("three")
>p foo1,foo2,foo3
>Output ->
># <Foo:0xb7d6b4f0 @id=2, @s="one">   # why is @id not 1
># <Foo:0xb7d6b4c8 @id=3, @s="two">   # and 2
># <Foo:0xb7d6b4a0 @id=4, @s="three"> # and 3 ?
>
>
>
>
>
>
>  
>