Removing an item from shopping cart array - php

Question

I'm building a shopping cart, I save the orders in a multidimensional array which is stored in a session, $_SESSION['cart']
A product is represented by something like
$product_array=array($id,$description,$price);
The multidimensional array is the array of the $product_array.s
The $id's are unique.
The issue is, When i want to remove a product from the multidimensional $_SESSION['cart']
array based on the id, it works if it's just one item in the cart, but if more, it doesn't work, the items seems to be removed but it's 'ghost' is left behind in the cart. The code
is something like this :
//get $id, $count is elements in array
for ($r = 0; $r <= $count-1; $r++)
{
if($_SESSION['cart'][$r][0]=="$id")
{
unset($_SESSION['cart'][$r]);
echo "<div class=success>The item has been removed from your shopping cart.</div>";
break;
}
}

Answer 1

try this one function and that is working for me
function remove_product($id){
$id=intval($id);
$max=count($_SESSION['cart']);
for($i=0;$i<$max;$i++){
if($id==$_SESSION['cart'][$i]['id']){
unset($_SESSION['cart'][$i]);
break;
}
}
$_SESSION['cart']=array_values($_SESSION['cart']);
if($_REQUEST['command']=='delete' && $_REQUEST['id']>0){
remove_product($_REQUEST['id']);
}
else if($_REQUEST['command']=='clear'){
unset($_SESSION['cart']);
}
else if($_REQUEST['command']=='update'){
$max=count($_SESSION['cart']);
for($i=0;$i<$max;$i++){
$id=$_SESSION['cart'][$i]['id'];
$q=intval($_REQUEST['qty'.$id]);
if($q>0 && $q<=999){
$_SESSION['cart'][$i]['qty']=$q;
}
else{
$msg='Some proudcts not updated!, quantity must be a number between 1 and 999';
}
}
}

Answer 2

Check if register_global is on in your php.conf. Try to use following syntax to unset both:
if($_SESSION['cart'][$r][0]=="$id") {
$_SESSION['cart'][$r] = NULL;// this is just to be sure =)
unset($_SESSION['cart'][$r], $cart[$r]);
echo "<div class=success>The item has been removed from your shopping cart.</div>";
break;
}

Answer 3

The following code works, maybe it will help You find what's wrong with Yours:
session_start();
$i=0;
$_SESSION['cart'][]=array($i++,'sds',99);
$_SESSION['cart'][]=array($i++,'sds',100);
$_SESSION['cart'][]=array($i++,'sds',20);
$_SESSION['cart'][]=array($i++,'sds',10);
$id = 2;
$count = count($_SESSION['cart']);
for ($r=0;$r<$count;$r++)
{
echo "num=$r<br>";
if(isset($_SESSION['cart'][$r]) && $_SESSION['cart'][$r][0]==$id)
{
unset($_SESSION['cart'][$r]);
echo "The item has been removed from your shopping cart.<br>";
break;
}
}
session_write_close();

Answer 4

As stated I think the issue has to do with the layout of your array and what you try to check against in your for loop or perhaps some PHP setting. Have you initiated a session for example? I would probably move to use an array of product references. Working with plain arrays can quickly become a nightmare where you accidently reference the wrong object without any kind of warning etc. Encapsulated objects fetched with well formed function names helps avoid this.
Something like
$cart = array($productId => $quantity, $productId2 => $quantityOfSecondProduct);
And then have an array that has all the product info data
$products = array($product1...);
where each product is of the type
class Product
{
$productId;
$productName;
$productDescription;
... etc
}
Then you have all the data separated but easily accessible and you can delete one or more entries in the cart based on the products id easily but just referencing it and deleting if quantity is 0.
if(($cart[$productId] - $quantityToRemove) <= 0)
unset($cart[$productId]);
else
$cart[$productId] -= $quantityToRemove;
Note that filling the products etc should preferably be done from some data source, I would also have put the entire cart as a class with nice functions and a bit more error checking should be in place ;)