如何从用作会话购物车的数组中删除商品ID

Question

I have a SESSION['cart'] with ID numbers only. I have a form passing the ID with a remove button. Once passed to my controller, I cannot figure out how to write the code that uses the ID ($_POST['id']) to delete the item from the SESSION['cart'].

I can loop through and display the array contents, but I cannot figure out how to delete based on ID passed from the form.

How do I loop through the SESSION['cart'] array to find a match with the ID passed from my delete form, and then delete that ID? I know that unset($_SESSION['cart'][X] deletes the ID at index X, but I cannot figure out how to loop through all the elements to find a match.

I have read a number of related issues in this forum but have been unable to apply any of those solutions to resolve this challenge. Any assistance is appreciated.

Answer 1

The way you have your values ( $products = array(3,7,99,152) ) isn't a very good method. Every time you want to perform an action, you have to loop through the array, you don't want that . Apart from that, how do you store quantity? Or variations like eg size or color?

if your structure is $array[ ID_OF_PRODUCT ] , you can simply do this:

unset( $_SESSION['cart'][$_POST['id']] ); // Instant access via the key!

---

This should be the method to use . This allows you to create an array like this, with advanced info, but with easy access (42/63 are example id's)

$_SESSION['cart']['products'][42] = array(
    'quantity' = 11,
    'size'     = 'large',
    'color'    = 'blue'
);
$_SESSION['cart']['products'][63] = array(
    'quantity' = 9,
    'size'     = 'small',
    'color'    = 'red'
);

This way you can access a lot of info with the product ID, and now also see which size and color (both just examples) the user selected. You may not have need for this now, but you will further down the road :)
As you might see, you can easily do stuff with the item:

isset($_SESSION['cart'][$_POST['id']]); // check if the product exists
unset($_SESSION['cart'][$_POST['id']]); // remove the product
echo $_SESSION['cart'][$_POST['id']]['quantity']; // get the quantity.

Not a loop in the code. You should only use loops when you have to, try to somewhat avoid them because often their slow. Say you have an extreme case of 1000 items in your shop, and you need to delete no999... That'll take a noticable moment.

Answer 2

Here is the code to do it right:

$id = $_POST['id'];
$items = $_SESSION["cart"];
if(($key = array_search($id, $items)) !== false) {
    unset($items[$key]);
}
$_SESSION["cart"] = array_values($items);

Advice

Beside item ID, you can also sve item count in SESSION array because user can add several times same item into cart. In that case your $_SESSION["card"] should be structured like:

array(
    '1'=>12,//Item with ID=1 is added 12 times in shopping cart
    '17'=>2,//Item with ID=17 is added 2 times in shopping cart etc.
    '32'=>12,
)