Hi there,
Many thanks for your answer. I've also gone through your example and it took
me 10 minutes to understand how the operator precedence was working there.
Was expecting 1 on the first call :)
But this is not the point. You've nailed my question very preciseley in your
first answer: 'the preceding line is only run on the first call to the
function'.
My only question is (at it is related to the nature of the online manual):
how do you know it and I don't? This thing is the only logical explanation
to the fact the $a doesn't get initialized again to 0 in any subsequent call
to the function, but it's not written anywhere in the manual page. And it
seems the most important statement in my opinion, that justifies what I see
as an exception to a normal flow.
Hope all this makes sense.
Thanks,
S
In 4/3/08 13:14, Jochem Maas, jochem@xxxxxxxxxxxxx ha scritto
> Svevo Romano schreef:
>> Hello,
>>
>> I got this e-mail address from the ŒAdd note¹ page within the php.net
>> website. I was going to post something that was a question and I realised I
>> was in the wrong place :)
>>
>> I have 2 basic questions and I¹m sorry if they may seem too basic. I¹m a bit
>> new to php.
>>
>> The first question has to do with the static variables. I understand how
>> this works from the examples, but there is something that I cannot seem to
>> find clearly stated anywhere on that page.
>>
>> The example:
>>
>> <?php
>> function Test()
>> {
>> static $a = 0;
>
> the preceding line is only run on the first call to the function.
>
>> echo $a;
>> $a++;
>> }
>> ?>
>>
>> Of course works (I¹ve tested it on my server), but it is still obscure to
>> me, according to general programming principles, since I¹m still assigning
>> zero (0) to $a on each call to the Test function. How does this exactly work
>> when the static word is found? Is there and index that keeps track of each
>> call to the function ignoring any assignment in subsequent calls to the
>> function? Why doens¹t this work when you assign an expression result to the
>> variable?
>
> do something like
>
> function Test()
> {
> static $a;
>
> if (!isset($a))
> $a = 0;
> if ($a % 2)
> $a = $a * 2;
>
> echo $a++;
> }
>
>>
>> The second question has to do with the online manual. I¹ve found several
>> things on that manual specified in comments and not in the actual manual
>> part of it. What is the nature of the manual? Contributions from voluteers?
>> Is there any official manual I can buy that documents everything about the
>> language from the source? Or any official company that maintains the
>> language and that possibly offers support as well?
>
> php.net/ is the official manual. recommended to read it in english so your
> looking at the latest version (not always the case in other languages).
>
> user notes/comments are exactly that - notes, tips, gotcha's, examples related
> to whatever is documented on a given manual page. occasionally some of the
> best
> user notes are merged into the official documentation.
>
>>
>> Many thanks in advance for your time.
>>
>
