question about variable's scope

**Klarth** · Feb 27 '07, 03:25 AM

Re: question about variable's scope

On Feb 27, 11:59 am, "finer recliner" <finerrecli...@ gmail.comwrote:

i've been playing with the below code for a while now, and i cant get
it to work correctly. the user should be able to input text into a
textbox and upon hitting submit, it will append that text to whatever
is in "newpage.ht ml" and write this new chunk of text to data.txt.
>
the final result of my code will be a bit more elaborate, but i can't
even get this to work. i believe soemthing is wrong the scope of my
variables or how my functions are written or something. it seems
everytime i hit submit, only $text is written to data.txt. $above
seems to be blank in the addHTML function. any suggestions?
>
thanks!
-dave
>
/////////////////////////start code ////////////////////////////////
<html>
<head>
<?php
if ($submit) {
$newdata = addHTML($newdat a);
$fp = fopen("data.txt ", "w");
fwrite($fp, $newdata);
fclose($fp);
>
}
>
$fcurrent = fopen("newpage. html", "r");
$i = 0;
while(!feof($fc urrent)){
$line = fgets($fcurrent , 4096);
$above .= $line;}
>
fclose($fcurren t);
>
function addHTML($text){
global $above;
$newdata = $above . $text;
return $newdata;
>
}//end addHTML
>
?>
</head>
<body>
<form action="<? print $PHP_SELF; ?>" method="post">
<textarea name="newdata" rows="30" cols="80"></textarea>
<br>
<input type="submit" name="submit" value="Submit">
</form>
</body>
</html>
//////////////////////////////////end
code//////////////////////////////////////////

Look at the order of your statements. You are calling your addHTML
function before that makes use of the global variable $above, before
$above gets set.

**Jerry Stuckle** · Feb 27 '07, 04:15 AM

Re: question about variable's scope

finer recliner wrote:

i've been playing with the below code for a while now, and i cant get
it to work correctly. the user should be able to input text into a
textbox and upon hitting submit, it will append that text to whatever
is in "newpage.ht ml" and write this new chunk of text to data.txt.
>
the final result of my code will be a bit more elaborate, but i can't
even get this to work. i believe soemthing is wrong the scope of my
variables or how my functions are written or something. it seems
everytime i hit submit, only $text is written to data.txt. $above
seems to be blank in the addHTML function. any suggestions?
>
thanks!
-dave
>
>
/////////////////////////start code ////////////////////////////////
<html>
<head>
<?php
if ($submit) {
$newdata = addHTML($newdat a);
$fp = fopen("data.txt ", "w");
fwrite($fp, $newdata);
fclose($fp);
}
>
$fcurrent = fopen("newpage. html", "r");
$i = 0;
while(!feof($fc urrent)){
$line = fgets($fcurrent , 4096);
$above .= $line;
}
fclose($fcurren t);
>
function addHTML($text){
global $above;
$newdata = $above . $text;
return $newdata;
}//end addHTML
>
?>
</head>
<body>
<form action="<? print $PHP_SELF; ?>" method="post">
<textarea name="newdata" rows="30" cols="80"></textarea>
<br>
<input type="submit" name="submit" value="Submit">
</form>
</body>
</html>
//////////////////////////////////end
code//////////////////////////////////////////
>

In addition to Klarth's comments, you shouldn't use global variables.
If you would have passed $above to this function (as a second parameter)
your problem would have been more obvious (just one of the reasons not
to use globals).

--
=============== ===
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
jstucklex@attgl obal.net
=============== ===

**finer recliner** · Feb 27 '07, 04:25 AM

Re: question about variable's scope

On Feb 26, 10:12 pm, "Klarth" <kah....@gmail. comwrote:

On Feb 27, 11:59 am, "finer recliner" <finerrecli...@ gmail.comwrote:
>
>
>

i've been playing with the below code for a while now, and i cant get
it to work correctly. the user should be able to input text into a
textbox and upon hitting submit, it will append that text to whatever
is in "newpage.ht ml" and write this new chunk of text to data.txt.

>

the final result of my code will be a bit more elaborate, but i can't
even get this to work. i believe soemthing is wrong the scope of my
variables or how my functions are written or something. it seems
everytime i hit submit, only $text is written to data.txt. $above
seems to be blank in the addHTML function. any suggestions?

>

thanks!
-dave

>

/////////////////////////start code ////////////////////////////////
<html>
<head>
<?php
if ($submit) {
$newdata = addHTML($newdat a);
$fp = fopen("data.txt ", "w");
fwrite($fp, $newdata);
fclose($fp);

>

}

>

$fcurrent = fopen("newpage. html", "r");
$i = 0;
while(!feof($fc urrent)){
$line = fgets($fcurrent , 4096);
$above .= $line;}

>

fclose($fcurren t);

>

function addHTML($text){
global $above;
$newdata = $above . $text;
return $newdata;

>

}//end addHTML

>

?>
</head>
<body>
<form action="<? print $PHP_SELF; ?>" method="post">
<textarea name="newdata" rows="30" cols="80"></textarea>
<br>
<input type="submit" name="submit" value="Submit">
</form>
</body>
</html>
//////////////////////////////////end
code//////////////////////////////////////////

>
Look at the order of your statements. You are calling your addHTML
function before that makes use of the global variable $above, before
$above gets set.

moving the addHTML function to the very beginning of my php block does
not change anything. I also tried moving it between the if(submit){}
block and the $fcurrent = fopen(...); line. no change. other ideas?

**OmegaJunior** · Feb 27 '07, 07:55 AM

Re: question about variable's scope

On Tue, 27 Feb 2007 05:06:02 +0100, Jerry Stuckle
<jstucklex@attg lobal.netwrote:

finer recliner wrote:

>i've been playing with the below code for a while now, and i cant get
>it to work correctly. the user should be able to input text into a
>textbox and upon hitting submit, it will append that text to whatever
>is in "newpage.ht ml" and write this new chunk of text to data.txt.
> the final result of my code will be a bit more elaborate, but i can't
>even get this to work. i believe soemthing is wrong the scope of my
>variables or how my functions are written or something. it seems
>everytime i hit submit, only $text is written to data.txt. $above
>seems to be blank in the addHTML function. any suggestions?
> thanks!
>-dave
> /////////////////////////start code ////////////////////////////////
><html>
><head>
><?php
>if ($submit) {
>$newdata = addHTML($newdat a);
>$fp = fopen("data.txt ", "w");
>fwrite($fp, $newdata);
>fclose($fp);
>}
> $fcurrent = fopen("newpage. html", "r");
>$i = 0;
>while(!feof($f current)){
> $line = fgets($fcurrent , 4096);
> $above .= $line;
>}
>fclose($fcurre nt);
> function addHTML($text){
> global $above;
> $newdata = $above . $text;
> return $newdata;
>}//end addHTML
> ?>
></head>
><body>
><form action="<? print $PHP_SELF; ?>" method="post">
><textarea name="newdata" rows="30" cols="80"></textarea>
><br>
><input type="submit" name="submit" value="Submit">
></form>
></body>
></html>
>//////////////////////////////////end
>code//////////////////////////////////////////
>>

>
In addition to Klarth's comments, you shouldn't use global variables. If
you would have passed $above to this function (as a second parameter)
your problem would have been more obvious (just one of the reasons not
to use globals).
>
>

Use $_POST[] instead.

I agree with Klarth: the order of the statements does not compute.
Suggestion: write down, in small sequential steps, how the script should
function. Make sure that every next step gets all its data from a previous
step. Then write the actual script.

--
Using Opera's revolutionary e-mail client: http://www.opera.com/mail/

**Toby A Inkster** · Feb 27 '07, 10:15 AM

Re: question about variable's scope

finer recliner wrote:

moving the addHTML function to the very beginning of my php block does
not change anything. I also tried moving it between the if(submit){}
block and the $fcurrent = fopen(...); line. no change. other ideas?

Moving the *definition* of the function does not change anything. Klarth
was referring to your *use* of the addHTML() function.

Firstly, forget about the definition of addHTML(). It's not relevant.
Imagine that addHTML() is some built-in PHP function so does not need
defining.

<?php
if ($submit) {
// At this point, you call addHTML().
// addHTML() tries to read a variable called $above.
// This $above variable has not been defined yet.
$newdata = addHTML($newdat a);
$fp = fopen("data.txt ", "w");
fwrite($fp, $newdata);
fclose($fp);
}
$fcurrent = fopen("newpage. html", "r");
$i = 0;
while(!feof($fc urrent)){
$line = fgets($fcurrent , 4096);
// Now you define $above, but it's too late!
$above .= $line;
}
fclose($fcurren t);
?>

The solution is to re-order you code like this:

<?php
$fcurrent = fopen("newpage. html", "r");
$i = 0;
while(!feof($fc urrent)){
$line = fgets($fcurrent , 4096);
$above .= $line;
}
fclose($fcurren t);

if ($submit) {
$newdata = addHTML($newdat a);
$fp = fopen("data.txt ", "w");
fwrite($fp, $newdata);
fclose($fp);
}

function addHTML($text){
global $above;
$newdata = $above . $text;
return $newdata;
}//end addHTML
?>

It has nothing to do with variable scope. If you do not understand why you
were having the problem, or why the solution above works, then you
*urgently* need to purchase a good book on imperative programming
techniques and read it from start to finish.

--
Toby A Inkster BSc (Hons) ARCS
Contact Me ~ http://tobyinkster.co.uk/contact
Geek of ~ HTML/SQL/Perl/PHP/Python*/Apache/Linux

* = I'm getting there!

**finer recliner** · Feb 27 '07, 03:15 PM

Re: question about variable's scope

On Feb 27, 4:56 am, Toby A Inkster <usenet200...@t obyinkster.co.u k>
wrote:

finer recliner wrote:

moving the addHTML function to the very beginning of my php block does
not change anything. I also tried moving it between the if(submit){}
block and the $fcurrent = fopen(...); line. no change. other ideas?

>
Moving the *definition* of the function does not change anything. Klarth
was referring to your *use* of the addHTML() function.
>
Firstly, forget about the definition of addHTML(). It's not relevant.
Imagine that addHTML() is some built-in PHP function so does not need
defining.
>
<?php
if ($submit) {
// At this point, you call addHTML().
// addHTML() tries to read a variable called $above.
// This $above variable has not been defined yet.
$newdata = addHTML($newdat a);
$fp = fopen("data.txt ", "w");
fwrite($fp, $newdata);
fclose($fp);
}
$fcurrent = fopen("newpage. html", "r");
$i = 0;
while(!feof($fc urrent)){
$line = fgets($fcurrent , 4096);
// Now you define $above, but it's too late!
$above .= $line;
}
fclose($fcurren t);
?>
>
The solution is to re-order you code like this:
>
<?php
$fcurrent = fopen("newpage. html", "r");
$i = 0;
while(!feof($fc urrent)){
$line = fgets($fcurrent , 4096);
$above .= $line;
}
fclose($fcurren t);
>
if ($submit) {
$newdata = addHTML($newdat a);
$fp = fopen("data.txt ", "w");
fwrite($fp, $newdata);
fclose($fp);
}
>
function addHTML($text){
global $above;
$newdata = $above . $text;
return $newdata;
}//end addHTML
?>
>
It has nothing to do with variable scope. If you do not understand why you
were having the problem, or why the solution above works, then you
*urgently* need to purchase a good book on imperative programming
techniques and read it from start to finish.
>
--
Toby A Inkster BSc (Hons) ARCS
Contact Me ~http://tobyinkster.co.uk/contact
Geek of ~ HTML/SQL/Perl/PHP/Python*/Apache/Linux
>
* = I'm getting there!

reordering the script worked this time :) thanks for all your help.

i understand the reason behind the problem now. variable scope was
just a guess when i originally posted since my $above seemed to lose
its value in between statements. anyways thanks again.

question about variable's scope

question about variable's scope

Comment

Comment

Comment

Comment

Comment

Comment