Empty and logical expressions

[Ralph DiMola]

Mark,

Thanks! Did some serious searching and I ran into this case once in all my
LC apps and libraries.

Here's an interesting exercise I just did.......

(Null < 0) ==> true
(Empty < 0) ==> true
(Empty = Null) ==> false

Based on your info, this is what I would have expected.

Ralph DiMola
IT Director
Evergreen Information Services
rdimola at evergreeninfo.net


-----Original Message-----
From: use-livecode [mailto:use-livecode-bounces at lists.runrev.com] On Behalf
Of Mark Schonewille
Sent: Thursday, November 08, 2012 4:25 PM
To: How to use LiveCode
Subject: Re: Empty and logical expressions

Hi Ralph,

Empty is a value too, but I wouldn't know how to evaluate it. Perhaps empty
evaluates to NULL internally, which would give the same result: NULL < 0 is
also true. Actually, NULL is less than any other value. Empty < 0 has been
true since the beginning of HyperCard.

--
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Mark Schonewille

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On 8 nov 2012, at 22:03, Ralph DiMola wrote:

> I just ran down a bug because.....
> 
> (empty<0) evaluates to true. I would have thought empty is only equal 
> to empty(or "") and any other logical test would be false.
> 
> Is this common knowledge or did I miss something in the docs?
> 


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