Multidimensional array in php SESSION - php

Question

I am having problem with updating an array element with in $_SESSION variable of PHP. This is the basic structure:
$product = array();
$product['id'] = $id;
$product['type'] = $type;
$product['quantity'] = $quantity;
And then by using array_push() function I insert that product in SESSION variable.
array_push($_SESSION['cart'], $product);
Now this is the main part where i m facing problem:
foreach($_SESSION['cart'] as $product){
if($id == $product['id']){
$quantity = $product['quantity'];
$quantity += 1;
$product['quantity'] = $quantity;
}
}
I want to increment product quantity within $_SESSION['cart'] variable. How can I do that?

Answer 1

Don't blindly stuff the product into your session. Use the product's ID as the key, then it's trivial to find/manipulate that item in the cart:
$_SESSION['cart'] = array();
$_SESSION['cart'][$id] = array('type' => 'foo', 'quantity' => 42);
$_SESSION['cart'][$id]['quantity']++; // another of this item to the cart
unset($_SESSION['cart'][$id]); //remove the item from the cart

Answer 2

this not best answers for u...but hope can help u guys
im not expert coders, and just learn coding in this forum ^,^ .You must always trying to solved.
for more example hope can help to update value quantity:
<?php
if(isset($_POST['test'])) {
$id =$_POST['id'];
$newitem = array(
'idproduk' => $id,
'nm_produk' => 'hoodie',
'img_produk' => 'images/produk/hodie.jpg',
'harga_produk' => '20',
'qty' => '2'
);
//if not empty
if(!empty($_SESSION['cart']))
{
//and if session cart same
if(isset($_SESSION['cart'][$id]) == $id) {
$_SESSION['cart'][$id]['qty']++;
} else {
//if not same put new storing
$_SESSION['cart'][$id] = $newitem;
}
} else {
$_SESSION['cart'] = array();
$_SESSION['cart'][$id] = $newitem;
}
}
?>
<form method="post">
<input type="text" name="id" value="1">
<input type="submit" name="test" value="test">
<input type="submit" name="unset" value="unset">
</form>

Answer 3

I faced the same issue before, and the accepted answer works only because it modifies the session variable directly, but in a foreach loop, you must pass the $product variable by reference (by prepending & to it) to be able to save changes like this :
foreach($_SESSION['cart'] as &$product){
if($id == $product['id']){
$product['quantity'] += 1;
}
}
Or if you follow the accepted solution :
foreach($_SESSION['cart'] as $id => &$product){
if($searchId == $id){
$product['quantity'] += 1;
}
}