php购物车问题
<?php<br />
include ('book_sc_fns.php');<br />
// The shopping cart needs sessions, so start one<br />
session_start();<br />
<br />
@$new = $_GET['new'];<br />
<br />
if($new) {<br />
//new item selected<br />
if(!isset($_SESSION['cart'])) {<br />
$_SESSION['cart'] = array();<br />
$_SESSION['items'] = 0;<br />
$_SESSION['total_price'] ='0.00';<br />
}<br />
<br />
if(isset($_SESSION['cart'][$new])) {<br />
$_SESSION['cart'][$new]++;<br />
} else {<br />
$_SESSION['cart'][$new] = 1;<br />
}<br />
<br />
$_SESSION['total_price'] = calculate_price($_SESSION['cart']);<br />
$_SESSION['items'] = calculate_items($_SESSION['cart']);<br />
}<br />
<br />
if(isset($_POST['save'])) {<br />
foreach ($_SESSION['cart'] as $isbn => $qty) {<br />
if($_POST[$isbn] == '0') {<br />
unset($_SESSION['cart'][$isbn]);<br />
} else {<br />
$_SESSION['cart'][$isbn] = $_POST[$isbn];<br />
}<br />
}<br />
<br />
$_SESSION['total_price'] = calculate_price($_SESSION['cart']);<br />
$_SESSION['items'] = calculate_items($_SESSION['cart']);<br />
}<br />
<br />
do_html_header("Your shopping cart");<br />
<br />
if(($_SESSION['cart']) && (array_count_values($_SESSION['cart']))) {<br />
display_cart($_SESSION['cart']);<br />
} else {<br />
echo "<p>there are no items in your cart</p><div class="aritcle_card flexRow">
<div class="artcardd flexRow">
<a class="aritcle_card_img" href="/ai/1524" title="Face++旷视"><img
src="https://img.php.cn/upload/ai_manual/000/969/633/68b7a3057e494925.png" alt="Face++旷视" onerror="this.onerror='';this.src='/static/lhimages/moren/morentu.png'" ></a>
<div class="aritcle_card_info flexColumn">
<a href="/ai/1524" title="Face++旷视">Face++旷视</a>
<p>Face⁺⁺ AI开放平台</p>
</div>
<a href="/ai/1524" title="Face++旷视" class="aritcle_card_btn flexRow flexcenter"><b></b><span>下载</span> </a>
</div>
</div><hr/>";<br />
}<br />
<br />
$target = "index.php";<br />
<br />
// if we have just added an item to the cart, continue shopping in that category<br />
if($new) {<br />
$details = get_book_details($new);<br />
if($details['catid']) {<br />
$target = "show_cat.php?catid=".$details['catid'];<br />
}<br />
}<br />
display_button($target, "continue-shopping", "Continue Shopping");<br />
<br />
// use this if SSL is set up<br />
// $path = $_SERVER['PHP_SELF'];<br />
// $server = $_SERVER['SERVER_NAME'];<br />
// $path = str_replace('show_cart.php', '', $path);<br />
// display_button("https://".$server.$path."checkout.php",<br />
// "go-to-checkout", "Go To Checkout");<br />
<br />
// if no SSL use below code<br />
display_button("checkout.php", "go-to-checkout", "Go To Checkout");<br />
<br />
do_html_footer();<br />
?><br />
代码中的$_SESSION['cart'][$new]是什么意思,为什么要这样子做?










