Re: Bitwise NOT operator?

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On Tue, Aug 24, 2010 at 3:55 PM, Ford, Mike <M.Ford@xxxxxxxxxxxxxx> wrote:
>> -----Original Message-----
>> From: Andy McKenzie [mailto:amckenzie4@xxxxxxxxx]
>> Sent: 24 August 2010 17:24
>> To: php-general@xxxxxxxxxxxxx
>> Subject: Re:  Bitwise NOT operator?
>
>
>> From your example, this would have shown me what I needed to know:
>>
>> "Then taking the value of E_NOTICE...
>> 1000
>> ... and inverting it via ~:
>> 11111111111111111111111111110111"
>>
>> As it was, I assumed the 32-bit number was there because the author
>> wanted it there, not because PHP assumes those extra bits.
>
> That's not PHP. That's the underlying computer architecture, and PHP has no choice in the matter. (Well, assuming you leave BCMath and so on out of the equation!)
>
> Cheers!
>
> Mike


True, but largely irrelevant from my point of view:  I'm talking to
PHP.  Even if I'd thought about it in terms of the architecture, I
would have assumed that PHP would treat a two-bit number as a two-bit
number, even if it had to do some weirdness in the background because
it's not.  If I enter a decimal two, I know the computer deals with it
as binary, and now I know it probably deals with it as a 32-bit binary
number, but it doesn't show me all the extra bits:  it just shows me a
two.

My point here, much as it might sound like it, isn't that PHP is wrong
for doing things the way it does.  Even if I thought it is, I don't
know what I'm talking about, and I know it.  What I'm saying is that
the documentation doesn't even begin to indicate to people like me
that things won't work the way we expect.  Maybe that's not necessary;
certainly I've never needed it until now, and the confusion was easily
cleared up.  But adding to the docs might avoid a lot of confusion for
the next guy who doesn't really know what he's doing.

-Alex

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