From: Ilias Lazaridis <ilias@...>
Date: 2011-06-20T05:45:30+09:00
Subject: Re: CORE - Inconsistent Handling of Uninitialized Variables

(slightly corrected, order of variable types)

puts "\n== Testin in MAIN Context =="

$global = 'global'
@instance = 'instance'
@@class = 'class'
local = 'local'

puts "#$global, #@instance, #@@class, #{local}"

begin puts $empty_global == nil   rescue puts "undefined" end
begin puts @empty_instance == nil rescue puts "undefined" end
begin puts @@empty_class == nil   rescue puts "undefined" end
begin puts empty_local == nil     rescue puts "undefined" end


class VarTest
  puts "\n== Testin in Class Context =="

  $global = 'global'
  @instance = 'instance'
  @@class = 'class'
  local = 'local'

  puts "#$global, #@instance, #@@class, #{local}"

  begin puts $empty_global == nil   rescue puts "undefined" end
  begin puts @empty_instance == nil rescue puts "undefined" end
  begin puts @@empty_class == nil   rescue puts "undefined" end
  begin puts empty_local == nil     rescue puts "undefined" end

end

#OUTPUT

== Testin in MAIN Context ==
global, instance, class, local
true
true
undefined
undefined

== Testin in Class Context ==
global, instance, class, local
true
true
undefined
undefined


> The inconsistency:
>
> become nil, do not raise error:
> $empty_global
> @empty_instance
>
> are undefined, raise an error:
> empty_local
> @@empty_class
>
> -
>
> Is this a defect or is there an explanation for this behaviour?


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