From: Robert Klemme <shortcutter@...>
Date: 2008-05-02T23:35:04+09:00
Subject: Re: | versus || Any reason for this issue?

On 02.05.2008 16:15, Florian Gilcher wrote:
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> On May 2, 2008, at 4:01 PM, Iņaki Baz Castillo wrote:
> 
>> Hi, why in the second case the non declared "my_var" variable is
>> processed but not in the first case?
>>
>> irb> nil || 2 || my_var
>> => 2
>>
>> irb> nil | 2 | my_var
>> NameError: undefined local variable or method `my_var'
>>
>>
>> Of course, I prefer the first case: 2 is already true so there is no
>> reason to read the next "my_var". Also, it's not good for performance,
>> is it?
> 
> | is the bitwise OR and something entirely different from ||.

This is only mostly correct.  Semantics of | depend on the class that 
implements it.

irb(main):001:0> %w{a b c} | %w{c d e}
=> ["a", "b", "c", "d", "e"]
irb(main):002:0> %w{a b c} & %w{c d e}
=> ["c"]

Cheers

	robert