From: Gennady Bystritsky <Gennady.Bystritsky@...>
Date: 2009-11-16T00:51:11+09:00
Subject: Re: very newbie question


On Nov 15, 2009, at 1:04 AM, 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.

Not completely true. In Java, for instance, it will produce a compile error like:

Test.java:40: operator ! cannot be applied to int
        if(!0) {
           ^
1 error

> 
> 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
> 
> 
> Thank you.
>