From: Einar Karttunen <ekarttun@...>
Date: 2002-04-05T15:46:13+09:00
Subject: Re: True equality?

On 05.04 15:33, james@rubyxml.com wrote:
> This one-liner prints "true":
>   ruby -e "p 'true' if 1 "
> But this does not:
>   ruby -e "p 'true' if 1 == true"
> nor this:
>   ruby -e "p 'true' if true == 1"
> 

In if statements the values false and nil are false, and all other values are true.

In the first case is clearly true by the above definition.

The second and third case first evaluate the == expression and then 
apply if to the result. Now because 1==true => false, and true==1 =>false
the if statement is clearly not executed. == means equality at the object 
level and is usually overridden. It should return true iff both arguments
are the same object.

- Einar Karttunen