From: skim <skim.la@...>
Date: 2010-08-18T08:40:24+09:00
Subject: Re: Strange behavior of or condition in loop

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and/or aren't the same as &&/||.  they have lower operator precedence than
latter.

i recommend reading this article on the usage for both:
http://avdi.org/devblog/2010/08/02/using-and-and-or-in-ruby/

On Tue, Aug 17, 2010 at 17:50, AppleII717 <salex@mac.com> wrote:

> I don't understand why ruby's "or" acts differently in a loop.
>
> This is some code I pulled out of a rails model, expanded the
> assignments and simulated in IRB (1.8.7 and 1.9.2rc)
>
> #simple boolean assignments
> #Why does this work
>
>  dirty = false
>  found = true
>  dirty = dirty or found
>  puts dirty.to_s  => true
>
> #same type of assignments in loop giving meaning to dirty and found
>  #But this does not
>
>  a = ["score_method", "updated_at"]
>  dirty = false
>  a.each{|attrib|
>    puts dirty.to_s + " in "
>    found = !( /score_method|weight|critical|minimum_value/i =~
> attrib ).nil?
>    dirty = dirty or found
>    puts dirty.to_s + " out " + found.to_s
>  }
>  puts dirty.to_s => false
>
> #another version with parens  around or
>  #But this does
>
>  a = ["score_method", "updated_at"]
>  dirty = false
>  a.each{|attrib|
>    puts dirty.to_s + " in "
>    found = !( /score_method|weight|critical|minimum_value/i =~
> attrib ).nil?
>    dirty = (dirty or found)
>    puts dirty.to_s + " out " + found.to_s
>  }
>  puts dirty.to_s => true
>
>
> I've been doing to additive boolean assignment stuff forever without
> parens. Guess I just don't understand Ruby.
>
>

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