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Posted by Bent Stigsen on 07/18/06 05:59
Chung Leong wrote:
> Bent Stigsen wrote:
>> It's quite clearly stated in the manual, no problem there. I just
>> don't understand the choice of behavior.
>>
>> It is the concept of "isset", which I like to take literally.
>> When I set the variable to null, causing the variable to appear in
>> $GLOBALS, why should "isset" return false?
>>
>> I understand the behavior, not the choice.
>
> Part of the reason is the way the global and static keyword was
> implemented. These are operators, not declarations. When you use them
> on variables they create entries in the current symbol table. Thus if
> isset() behaves as you described, it'll always return true in the
> following:
>
> <?
>
> function bobo() {
> static $the_clown;
> if(isset($the_clown)) {
> }
> }
>
> ?>
>
> which wouldn't be rather unintuitive, since you never actually set the
> variable.
Yes, I guess it would, but I would say creating them in the first
place is unintuitive too. At least for global.
e.g.:
<?php
echo $a; //generates error, $a not in $GLOBALS
foo();
echo $a; //no error, $a is now in $GLOBALS
function foo() {
global $a;
echo $a; //no error
}
?>
It is not that I in a tight spot haven't made that kind of choice of
getting a feature at the cost of a less sensible behavior, in order to
avoid the need to rewrite a lot of code. But personally I would rather
just (temporarily) accept the odd effect of the modifiers, rather than
seeing other functions being adapted to it, if that is the case.
--
/Bent
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