quick php problem

[nvening]

Can someone explain why this throws up a parse error??

PHP Code:

<?php
$pd = $_GET['pd']; 
?>

...

<?php include ($pd'.php'); ?>

Thanks, Neil.

[sadbuttrue]

You need to concat the $pd and '.php' with a '.'.

include ($pd . '.php');

[nvening]

thats strange, i swear i tried that before and it didnt work :s - haha strange, thats for your help anyway, it works now!

[nvening]

Ok, next problem

PHP Code:

<a href="products.php?pd=<?php echo($pd++);?>">Next</a>

is not adding one to the $pd varible, it simply stays the same

edit:

Also how do would i make that link not display if the $pd++ variable was not set in my array?

Thanks

[aidanjt]

Do echo(++$pd) instead. $pd++ will return the value of $pd *then* increment by one. ++$pd does it the other way around (which is what you want).

As for your other problem, use an if statement, something like if($pd) { printlinkcode... }.

[Nelsaidi]

Validate your data! - Including whatever $_GET['pd'] has is a big security issue! There are tutorials, but best method tbh is limit what can be in the URL, so simply adding something like:
[code=php]if(!is_numeric($_GET['pd'])){ die(); }[/code] Will stop the page from loading because pd isnt numeric, you can use regular expressions to allow alpha numeric.

[nvening]

Ah, cheers for thatr aidanjt
And i came up with an if statment (i was a bit coded out when i couldnt work out how to do it last night!) but im having a strange issue.

The code is as follows:

PHP Code:

<?php
$next = ++$pd;
$previous = --$pd;

$product = array("ring","bracelet","anklet","earing");

if (array_key_exists($previous, $product))
{
echo "<a href=\"products.php?pd=".$previous."\">Previous</a>";
}
if (array_key_exists($next, $product))
{
echo "<a href=\"products.php?pd=".$next."\">Next</a>";
}
?>

The strange thing is that this works fine for the Next, with the link being removed when no more values exist, but the Previous results in $pd being echoed not --$pd.

Any ideas what could be causing this?

And thanks for the security tip, im working on something along those lines for when the code is more mature

[aidanjt]

$pd is being incremented, so when you decrement with --, then you're returning a number for the current page. Do something like this instead.

PHP Code:

$next = $pd + 1;
$previous = $pd - 1; 


[nvening]

That worked great thanks!

Could you explain why writing it out in long form, ie $pd + 1 is different from ++$pd??? I thought all ++ was was shorthand?

[aidanjt]

++$pd is shorthand for $pd = $pd + 1;, so what you were doing there was $next = $pd = $pd + 1;. Then, when you did $previous = --$pd what you did was $previous = $pd = $pd - 1; after $pd was already incremented, the value of $pd was changed back to it's original value and assigned to $previous and $pd.

[nvening]

urgh, this is getting irritating. Why is this if statment executing the if statment and not the elseif statment?

PHP Code:


$product = array("ring","bracelet","anklet","earing");
$page = "pd_det";

<?php
if ($page = "products")
{
include ("products/products.php");
}
elseif ($page = "pd_det")
{
include ("products/product_details/" . $product[$pd] . ".php");
}
?>

Code of products file

PHP Code:

<div id="pdcont">

<div id="pdimgcont">
<a id="pdimg" href="index.php?page=pd_det&pd=<?php echo("{$product[$pd]}");?>" title="<?php echo("{$product[$pd]}");?>"><span><?php echo("{$product[$pd]}");?></span></a>
</div>

<div id="sketchcont">
<img src="products/products_img/sketch/<?php echo("{$product[$pd]}");?>.jpg"/>

<?php if (array_key_exists($previous, $product))
{
echo "<a href=\"index.php?page=\products&pd=".$previous."\">Previous</a>";
}
if (array_key_exists($next, $product))
{
echo "<a href=\"index.php?page=\products&pd=".$next."\">Next</a>";
}
?>
</div>

</div>

[aidanjt]

one equal means assignment, two equals means comparison.

$page is always true because you're assigning a string to $page before evaluating it, which will always be true because it's not zero or unset.