From: Shyouhei Urabe <redmine@...>
Date: 2008-08-25T18:32:25+09:00
Subject: [ruby-dev:35951] [Bug #492] defined? a && defined? b

Bug #492: defined? a && defined? b
http://redmine.ruby-lang.org/issues/show/492

起票者: Shyouhei Urabe
ステータス: Open, 優先度: Normal
担当者: Yukihiro Matsumoto, カテゴリ: core

defined? a && defined? b がnilになります。両方定義されてるんだからnilはおかしいはずです。

  irb(main):001:0> [RUBY_VERSION, RUBY_REVISION]
  => ["1.9.0", 17576]
  irb(main):002:0> a = b = nil
  => nil
  irb(main):003:0> defined? a && defined? b
  => nil

1.8ではdefined?(a && defined? b)と解釈されて"expression"になります

  irb(main):001:0> [RUBY_VERSION, RUBY_REVISION]
  => ["1.8.7", 17572]
  irb(main):002:0> a = b = nil
  => nil
  irb(main):003:0> defined? a && defined? b
  => "expression"
  irb(main):004:0>


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