PHP-购物车，会话问题

Question

When an item is added to the cart the item id and the quantity of that item is supposed to be displayed. In this case only the quantity is being parsed from the session. the item ID is not being displayed. Also when a different item is added the cart should display a second item with a separate quantity.

<?php 
session_start();


?>
<?php 
if (isset($_POST['pid'])) {
    $pid = $_POST['pid'];
    $wasFound = false;
    $i = 0;

    if (!isset($_SESSION["cart_array"]) || count($_SESSION["cart_array"]) < 1){
        $_SESSION["cart_array"] = array(1 => array("item_id" => $pid, "quantity" => 1));
    } else {
        foreach ($_SESSION["cart_array"] as $each_item) {
            $i++;
            while (list($key, $value) = each($each_item)) {
                if ($key == "item_id" && $value == $pid) {
                array_splice($_SESSION["cart_array"], $i-1, 1,array(array("item_id" => $pid, "quantity" => $each_item['quantity'] + 1)));
                $wasFound = true;
               }
            }
        }
        if ($wasFound == false) {
        array_push($_SESSION["cart_array"], array("item_id" => $pid, "quantity" => 1));
    }
  }
 }
?>
<?php
if (isset($_GET['cmd']) && $_GET['cmd'] == "emptycart") {
    unset($_SESSION["cart_array"]);
}
?>
<?php
$cartOutput = "";
if (!isset($_SESSION["cart_array"]) || count($_SESSION["cart_array"]) < 1) {
    $cartOutput = "<h2 align='center'>Your shopping cart is empty</h2>";
} else {
    $i = 0;
    foreach ($_SESSION["cart_array"] as $each_item) {
        $i++;
        $cartOutput .= "<h2>Cart item $i</h2>";
        while (list($key, $value) = each ($each_item)) {
            $cartOutput .= "key:$value<br />";
        }
    }
}
?>

any suggestions? Thanks

Answer 1

That's some pretty weird array manipulation you have there. You should be able to do everything you need with one foreach loop:

    foreach ($_SESSION["cart_array"] as $item_key => $each_item) {
        if ( $each_item['item_id'] == $pid )
        {
            $_SESSION["cart_array"][$item_key]['quantity']++;
        }
        $wasFound = true;
    }

In case it's not familiar to you, foreach ( $foo as $key => $value ) is the normal way of doing what you have written as while( list($key, $value) = each($foo)) and $foo++ is short-hand for $foo = $foo + 1 .

You can actually make this even simpler if you use the product IDs as the keys of the shopping cart array; that way you can just ask PHP if the key exists, like so:

if ( array_key_exists($pid, $_SESSION['cart_array']) )
{
    $_SESSION['cart_array'][$pid]['quantity']++;
}
else
{
    $_SESSION['cart_array'][$pid] = array('item_id' => $pid, 'quantity' => 1);
}