I tested it using Ruby 1.8.6 patch 111 and also Ruby 1.9.0 (revision 15968).
var = nil if false var.nil? #=> true I actually saw it from tobi's blog, then I discussed with a perler who loves ruby as well, here's a copy paste. (Bottomline: is it a feature or a bug????) 12:52:37 PM edpratomo: kok bisa gitu? (yg irb itu) 12:52:49 PM Rie!: bug of the day -_- 12:52:56 PM edpratomo: ruby 1.9? 12:53:28 PM Rie!: 1.8.6 as well 12:55:09 PM edpratomo: oh i understand 12:55:31 PM edpratomo: var = nil if false creates var 12:56:01 PM Rie!: it's just like the stupid param variable is still available outside of the block/yield 12:56:07 PM edpratomo: irb(main):005:0> var = "blah" if false => nil irb(main):006:0> var => nil 12:56:32 PM edpratomo: so it's not a bug 12:56:58 PM edpratomo: ever got bitten by the leaky block scope? 12:57:18 PM Rie!: how come it's not a bug :-B var should be undefined local var 12:57:20 PM Rie!: not nil 12:57:51 PM edpratomo: try to post that to ruby-talk :-) i believe you will get "it's not a bug" replies 12:58:11 PM Rie!: that's from tobias luetjke blog 12:58:20 PM Rie!: so i believe many rubyists had noticed that 12:58:46 PM edpratomo: has been discussed in ruby-talk/core? 12:58:58 PM Rie!: haven't checked yet 1:00:02 PM edpratomo: imho it's not a bug. that foo = nil if false creates unitialized foo. 1:00:31 PM edpratomo: in perl iirc such expression will be caught 1:00:39 PM Rie!: well it shouldn't execute the command inside that if false 1:01:04 PM edpratomo: if the if clause is evaluated first. 1:03:56 PM edpratomo: perl -wle'my $foo = "ok" if 0; print $foo' Use of uninitialized value in print at -e line 1. 1:04:45 PM edpratomo: perl -Mstrict -wle'my $foo = "ok" if 0; print $foo' Use of uninitialized value in print at -e line 1 1:05:03 PM edpratomo: it's a warning. not error. 1:05:22 PM edpratomo: so $foo is created, but unitialized. 1:05:38 PM edpratomo: in perl it will issue warning [in bahasa indonesia] Saya sebetulnya melihat ini dari blog Tobi kemudian saya berdiskusi bersama seorang pengguna perl yang juga mencintai ruby, berikut tadi copy paste nya. (Inti dari pertanyaan saya adalah apakah ini fitur ataukah bug di ruby????) -- blog: http://tinyurl.com/2bjgvn, ruby: http://www.ruby-lang.org/id/about "Developer Time is expensive... Servers are cheap...", Ezra Zygmuntowicz - Merb
