From: Stefano Crocco <stefano.crocco@...>
Date: 2009-11-15T17:57:34+09:00
Subject: Re: very newbie question

On Sunday 15 November 2009, duxieweb wrote:
> |Hello,
> |
> |I run these in irb:
> |
> |irb(main):001:0> queue=0
> |=> 0
> |irb(main):002:0> if !queue then print "The queue is empty." end
> |=> nil
> |
> |why the result is nil?
> |I thought it should be printing "The queue is empty."
> |
> |Thanks.
> |

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.

I hope this helps

Stefano