From: Marnen Laibow-Koser <marnen@...>
Date: 2009-11-16T01:00:16+09:00
Subject: Re: very newbie question

duxieweb wrote:
> 2009/11/15 Stefano Crocco <stefano.crocco@alice.it>:
> 
>>
>> Because 0 is a true value in ruby, so !queue is false and the body of the if
>> expression is not executed. In ruby, the only false values are false and nil.
>>
> 
> Oh, that sounds so different from other languages that 0 is a true 
> value.
> 
> python:
>>>> x=0
>>>> if (not x):
> ...   print "x is false"
> ...
> x is false
> 
> perl:
> # perl -le '$x=0; print "x is false" if not $x'
> x is false
>

Perl has the additional complication that certain math operations will 
return the string "0 but true", which is transparently converted to 0 in 
a numeric context but still evaluates to true.  So does 0.0, IIRC.

> 
> Thank you.

Best,
--
Marnen Laibow-Koser
http://www.marnen.org
marnen@marnen.org
-- 
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