[SOLVED] Frustrating syntax warning

[KevinM1]

Yes, this is the same one as before, but I figure I might get a response if I put all of the info in one post.

I'm getting the following warning: [quote]Warning: Invalid argument supplied for foreach() in /home/thinkin8/php_classes/ShoppingCart.php on line 27[/quote]

This is the code utilizing the ShoppingCart class (it's autoloaded through the included config.php):
[code]
<?php

include('../php_config/config.php');

session_start();
ob_start();

if(!isset($_SESSION['ip'])){
  $ip = $_SERVER['REMOTE_ADDR'];
  $myCart = new ShoppingCart();
}

else{
  if($_SERVER['REMOTE_ADDR'] != unserialize(urldecode($_SESSION['ip']))){
      $ip = $_SERVER['REMOTE_ADDR'];
      $myCart = new ShoppingCart();
  }

  else{
      $ip = unserialize(urldecode($_SESSION['ip']));
      $myCart = unserialize(urldecode($_SESSION['myCart']));
  }
}

include('../templates/header.inc');

echo "IP address: $ip<br />\n";
$myCart -> showCart();

echo <<<EOT
<div>
  <img src="images/store/storefront_01.jpg" alt="" /><img src="images/store/storefront_02.jpg" alt="" />
</div>

<div>
  <a href="viewcat.php?cat=acer_laptops"><img src="images/store/storefront_05.jpg" alt="" /></a>
  <img src="images/store/storefront_06.jpg" alt="" />
  <a href="viewcat.php?cat=lenovo_laptops"><img src="images/store/storefront_04.jpg" alt="" /></a>
</div>

<div>
  <a href="viewcat.php?cat=averatec_laptops"><img src="images/store/storefront_09.jpg" alt="" /></a>
  <a href="viewcat.php?cat=panasonic_laptops"  style="margin-left: 68px;"><img src="images/store/storefront_11.jpg" alt="" /></a>
</div>

<div>
  <img src="images/store/storefrontbar.jpg" alt="" />
</div>

<div>
  <a href="viewcat.php?cat=acer_desktops"><img src="images/store/storefront_05.jpg" alt="" /></a>
  <img src="images/store/desktop.jpg" style="margin-left: 25px; alt="" />
  <a href="viewcat.php?cat=lenovo_desktops" style="margin-left: 30px;"><img src="images/store/storefront_04.jpg" alt="" /></a>
</div>

<div>
  <a href="#"><img src="images/store/storefront_19.jpg" alt="" /></a>
  <a href="viewcat.php?cat=dandh_desktops" style="margin-left: 53px;"><img src="images/store/storefront_21.jpg" alt="" /></a>
</div>

<div>
  <img src="images/store/storefrontbar.jpg" alt="" />
</div>

<div>
  <a href="viewcat.php?cat=peripherals"><img src="images/store/storefront_24.jpg" alt="" /></a>
</div>

<div>
  <img src="images/store/storefront_25.jpg" alt="" />
</div>
EOT;

include('../templates/footer.inc');

$_SESSION['ip'] = urlencode(serialize($ip));
$_SESSION['myCart'] = urlencode(serialize($myCart));

ob_end_flush();

?>
[/code]

This is the ShoppingCart class itself.  As you can see, line 27 is the foreach of the showCart method
[code]
<?php

class ShoppingCart{
  private $Cart;

  public function addProduct($name, $price, $quantity){
      $this -> Cart[] = new Product($name, $price, $quantity);
  }

  public function clearCart(){
      $this -> Cart = array();
  }

  public function getTotal(){
      $total = 0;

      foreach($this -> Cart as $value){
        $total += $value -> getPrice();
      }

      return $total;
  }

  public function showCart(){
      echo "<table><tr><th>Name:</th><th>Quantity:</th><th>Total Price:</th></tr>\n";

      foreach($this -> Cart as $value){
        echo "<tr><td>{$value->getName()}</td><td>{$value->getQuan()}</td><td>\${$value->getPrice()}</td></tr>\n";
      }
      echo "</table>\n";
  }
}

?>
[/code]

Another poster suggested that having a $myCart variable with an empty $Cart property was causing the warning.  This is not the case, however, as my test script, with an empty cart, generates no warnings whatsoever.  My test code:
[code]
<?php

#test3.php -- test to see if the shopping cart works

include('../php_config/config.php');

$cart = new ShoppingCart();

$cart -> addProduct('tomato', 0.99, 5);
$cart -> addProduct('Nike Shoes', 50.99, 1);
$cart -> addProduct('Playstation 3', 600.00, 1);

$cart -> showCart();

$total = $cart -> getTotal();

echo "<br />\nTotal price of the items in your shopping cart: \${$total}<br />\n";

$cart -> clearCart();

$cart -> showCart();

$total = $cart -> getTotal();

echo "<br />\nTotal price of the items in your shopping cart: \${$total}<br />\n";

?>
[/code]

In this script, showCart works flawlessly, even after clearCart is called.  No warnings at all.  What makes this so frustrating is that both scripts (my test script and my live script) are on the same server, so they're both running the same version of PHP (5.1.6) and they're both using the same ShoppingCart file, as there's only one on the server.

So, is this a case of PHP acting buggy?  Or is there anything else I can try?

Thanks.

[redbullmarky]

it could be a case of your error_reporting level as to why you're getting the error on one and not the other.
you could always do a check just before the 'foreach' such as:

[code]
<?php
if (sizeof($this->Cart) == 0)
{
  return;
}
?>
[/code]

the invalid argument would be a result of the foreach being passed something other than an array (including a null value). you can also try changing the $Cart declaration in your class to:

[code]
<?php
  private $Cart = array();
?>
[/code]

[KevinM1]

[quote author=redbullmarky link=topic=119095.msg487249#msg487249 date=1166446619]
the invalid argument would be a result of the foreach being passed something other than an array (including a null value). you can also try changing the $Cart declaration in your class to:

[code]
<?php
   private $Cart = array();
?>
[/code]
[/quote]

That did the trick!  Thanks a lot! :)