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Re: When "static" isn't "static"

Posted by Oli Filth on 12/05/05 21:56

comp.lang.php said the following on 05/12/2005 19:38:
> Wow, ok, that was a surprise! I didn't think isset() had the ability
> to declare a variable on the fly like that.

It doesn't.

> I was under the impression
> that it only checked for instantiation

It does.

> which would be implied that if
> a variable is not yet declared, it certainly could never be
> instantiated as you cannot instantiate a nonexistent entity.

??

>
> That solved the problem but potentially opened up a big PHP logic flaw
> in the process.
>
>
> Oli Filth wrote:
>
>>comp.lang.php said the following on 05/12/2005 19:02:
>>
>>>[PHP]
>>>function blah($item) {
>>> if (!isset($baseDir)) {
>>> static $baseDir = '';
>>> $baseDir = $item;
>>> print_r("baseDir = $baseDir\n");
>>> }
>>>
>>> $dirID = opendir($item);
>>> while (($fyl = readdir($dirID)) !== false) {
>>> if (is_dir("$baseDir/$fyl")) blah($item);
>>> // DO OTHER STUFF IF IT IS A FILE
>>> }
>>>}
>>>[/PHP]
>>>
>>>I am using PHP 4.3.2 and the following occurs within blah() :
>>>
>>>[Quote]
>>>baseDir = /home/me/stuff
>>>baseDir = /home/me/stuff/.
>>>baseDir = /home/me/stuff/./..
>>>[/Quote]
>>>
>>>I was under the impression that a static variable retains its value
>>>throughout a function (or method) recursive memory stack. However, it
>>>changes everytime because it apparently loses its set value.
>>
>>You are using $baseDir before you have declared it static, so PHP treats
>>it as non-static.
>>
>>
>>--
>>Oli
>
>


--
Oli

 

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