From: Markus Fischer <markus@...>
Date: 2011-06-22T05:37:31+09:00
Subject: [ruby-core:37269] [Ruby 1.9 - Bug #4914] Array#index fails when used in if statement assignment


Issue #4914 has been updated by Markus Fischer.


It "works" for me if you change the `&&` to `and`; so I think it's a precedence issue you're facing here.

I think this blog post here has some good examples which I think directly apply to your case: http://blog.jayfields.com/2007/08/ruby-operator-precedence-of-and-which.html
----------------------------------------
Bug #4914: Array#index fails when used in if statement assignment
http://redmine.ruby-lang.org/issues/4914

Author: Benjamin ter Kuile
Status: Open
Priority: Normal
Assignee: 
Category: 
Target version: 
ruby -v: 1.9.2p180 (2011-02-18 revision 30909) [x86_64-linux]


cat /etc/issue: Ubuntu 11.04
rvm -v: rvm 1.6.2
rvm 1.9.2, ruby -v: ruby 1.9.2p180 (2011-02-18 revision 30909) [x86_64-linux]
Also tested with: rvm 1.9.2-head, ruby -v: ruby 1.9.2p274 (2011-06-06 revision 31932) [x86_64-linux]

Test code:

a = [:a, :b, :c]
for k in 'a'..'c'
  if i = a.index(k.to_sym) && k.to_s =~ /b/
    puts i
  end
end
for k in 'a'..'c'
  i = a.index(k.to_sym)
  if i && k.to_s =~ /b/
    puts i
  end
end

output:
0
1

expected output:
1
1


-- 
http://redmine.ruby-lang.org