PHP Variables unloading

yeah yeah yeah! Thanks Joe! I think that's exactly what I'm lookin gfor.

All these search engines work great - if you know wha tto search for. I
invariably choose the worst wording.

Thanks agina mate!

Jon
"Joe Makowiec" <makowiec@invalid.invalid> wrote in message
news:Xns9829B80111472makowiecatnycapdotrE@216.104.212.96...
> On Thu 24 Aug 2006 05:44:52p, crash wrote in
> macromedia.dreamweaver.appdev:
>
>>> the only way I know would be to do something like
>>>
>>> $myvar = '';
>>
>> That's what I was afraid of. It might be so, I just wish I could use
>> the isset to check and see ifthey're still valid or not. I'm betting
>> that if $myVar = '', it will still be T for isset.
>
> There is, however, this:
>
> http://www.php.net/manual/en/function.unset.php
>
> Haven't tried it myself. !@#$, that search function at php.net works
> wonders...

Thanks David for the help!

yeah yeah yeah! Thanks Joe! I think that's exactly what I'm lookin gfor.

All these search engines work great - if you know wha tto search for. I
invariably choose the worst wording.

Thanks agina mate!

Jon
"Joe Makowiec" <makowiec@invalid.invalid> wrote in message
news:Xns9829B80111472makowiecatnycapdotrE@216.104.212.96...
> On Thu 24 Aug 2006 05:44:52p, crash wrote in
> macromedia.dreamweaver.appdev:
>
>>> the only way I know would be to do something like
>>>
>>> $myvar = '';
>>
>> That's what I was afraid of. It might be so, I just wish I could use
>> the isset to check and see ifthey're still valid or not. I'm betting
>> that if $myVar = '', it will still be T for isset.
>
> There is, however, this:
>
> http://www.php.net/manual/en/function.unset.php
>
> Haven't tried it myself. !@#$, that search function at php.net works
> wonders...

Joe Makowiec wrote:
>>That's what I was afraid of. It might be so, I just wish I could use
>>the isset to check and see ifthey're still valid or not. I'm betting
>>that if $myVar = '', it will still be T for isset.
>
> For some reason, and maybe it's the servers/version of PHP I'm on, I've
> never gotten good results out of isset().

No, you've got good results out of isset(). A variable that has been
defined returns true with isset(). To test for a variable that has no
value, use empty().

As you have just discovered in your other post, unset() removes a
variable entirely.

--
David Powers
Adobe Community Expert
Author, "Foundation PHP for Dreamweaver 8" (friends of ED)
http://foundationphp.com/

On Thu 24 Aug 2006 05:44:52p, crash wrote in
macromedia.dreamweaver.appdev:

>> the only way I know would be to do something like
>>
>> $myvar = '';
>
> That's what I was afraid of. It might be so, I just wish I could use
> the isset to check and see ifthey're still valid or not. I'm betting
> that if $myVar = '', it will still be T for isset.

There is, however, this:

http://www.php.net/manual/en/function.unset.php

Haven't tried it myself. !@#$, that search function at php.net works
wonders...

On Thu 24 Aug 2006 05:44:52p, crash wrote in
macromedia.dreamweaver.appdev:

> That's what I was afraid of. It might be so, I just wish I could use
> the isset to check and see ifthey're still valid or not. I'm betting
> that if $myVar = '', it will still be T for isset.

For some reason, and maybe it's the servers/version of PHP I'm on, I've
never gotten good results out of isset(). I try it, but invariably wind up
back at strlen($whatever) == 0 ?.

> I'm not sure I follow you here. Are you saying that you want to limit
> the scope of the PHP variables to the included file, so that in something
> like this:
>
> <?php
> include_once('fileA.inc');
> include_once('fileB.inc');
> include_once('fileC.inc');
> ?>
>
> you can have a variable, say $crashsVariable, in fileA.inc, fileB.inc and
> fileC.inc, and have it take on a separate value in each of them, but not
> affect any of the others?
>
> Without doing any experimentation... Using the include_once()s makes the
> include files, and thus all their code, part of the larger code block.
> AFAIK, the scope of a variable would be the calling file, so the answer
> would be no.

That supports my testing. Currently, I have my connection file included in
the main body of the document, my 'most common' recordsets included in
another file, and gerneralFunctions included in a third. These three
operate seamlessly together.



> However, within user-defined functions a local function scope is
> introduced. Any variable used inside a function is by default limited
> to the local function scope.
>
> So if you use $crashsVariable within a function within the included file
> (or, for that matter, the main file), it's local in scope. Otherwise, a
> variable exists for the entire page.

Agreed, again my testing supports this as well and sit is working on this
principle.

> the only way I know would be to do something like
>
> $myvar = '';

That's what I was afraid of. It might be so, I just wish I could use the
isset to check and see ifthey're still valid or not. I'm betting that if
$myVar = '', it will still be T for isset.

On Thu 24 Aug 2006 04:36:46p, crash wrote in
macromedia.dreamweaver.appdev:

> I have a lot of included files in my site. At the end of each included
> file, I close the sql, but would also like to close the variables used
> to produce the HTML.
>
> I'm having a hard time with my searching getting some relevant
> results. Can somebody help me here on what I"m looking for?

I'm not sure I follow you here. Are you saying that you want to limit
the scope of the PHP variables to the included file, so that in something
like this:

<?php
include_once('fileA.inc');
include_once('fileB.inc');
include_once('fileC.inc');
?>

you can have a variable, say $crashsVariable, in fileA.inc, fileB.inc and
fileC.inc, and have it take on a separate value in each of them, but not
affect any of the others?

Without doing any experimentation... Using the include_once()s makes the
include files, and thus all their code, part of the larger code block.
AFAIK, the scope of a variable would be the calling file, so the answer
would be no.

The PHP docs[1] have this to say:

The scope of a variable is the context within which it is defined.
For the most part all PHP variables only have a single scope. This
single scope spans included and required files as well.

but go on to add:

However, within user-defined functions a local function scope is
introduced. Any variable used inside a function is by default limited
to the local function scope.

So if you use $crashsVariable within a function within the included file
(or, for that matter, the main file), it's local in scope. Otherwise, a
variable exists for the entire page.

If you've spent the include file building a long string of text, which is
eventually output as HTML:

<?php
$myvar = "<head>\n";
$myvar .= "<title>$myDynamicTitle</title>\n";
...
echo $myvar;
?>

the only way I know would be to do something like

$myvar = '';

Hopefully David Powers or somebody who actually knows might check in.

[1] http://www.php.net/variables.scope