<?php include ('book_sc_fns.php'); // The shopping cart needs sessions, so start one session_start(); @$new = $_GET['new']; if($new) { //new item selected if(!isset($_SESSION['cart'])) { $_SESSION['cart'] = array(); $_SESSION['items'] = 0; $_SESSION['total_price'] ='0.00'; } if(isset($_SESSION['cart'][$new])) { $_SESSION['cart'][$new]++; } else { $_SESSION['cart'][$new] = 1; } $_SESSION['total_price'] = calculate_price($_SESSION['cart']); $_SESSION['items'] = calculate_items($_SESSION['cart']); } if(isset($_POST['save'])) { foreach ($_SESSION['cart'] as $isbn => $qty) { if($_POST[$isbn] == '0') { unset($_SESSION['cart'][$isbn]); } else { $_SESSION['cart'][$isbn] = $_POST[$isbn]; } } $_SESSION['total_price'] = calculate_price($_SESSION['cart']); $_SESSION['items'] = calculate_items($_SESSION['cart']); } do_html_header("Your shopping cart"); if(($_SESSION['cart']) && (array_count_values($_SESSION['cart']))) { display_cart($_SESSION['cart']); } else { echo "There are no items in your cart
"; } $target = "index.php"; // if we have just added an item to the cart, continue shopping in that category if($new) { $details = get_book_details($new); if($details['catid']) { $target = "show_cat.php?catid=".$details['catid']; } } display_button($target, "continue-shopping", "Continue Shopping"); // use this if SSL is set up // $path = $_SERVER['PHP_SELF']; // $server = $_SERVER['SERVER_NAME']; // $path = str_replace('show_cart.php', '', $path); // display_button("https://".$server.$path."checkout.php", // "go-to-checkout", "Go To Checkout"); // if no SSL use below code display_button("checkout.php", "go-to-checkout", "Go To Checkout"); do_html_footer();?> 代码中的$_SESSION['cart'][$new]是什么意思，为什么要这样子做？
回复讨论(解决方案)
你打印你的$_SESSION看看就知道的。
$_SESSION 中储存了一个叫cart 的数组对象，取出来就是$_SESSION['cart'] $new是这个数组的键值，取法就是$_SESSION['cart'][$new]了