PHP代码中未定义的索引？

-1

我的PHP代码有一些问题。对于变量“$ total”，我有一个未定义的索引错误。我需要一些帮助来解决这个问题。这是我的整个PHP代码。PHP代码中未定义的索引？

<?php 
include('inc/connect.php'); 
session_start(); 
?> 
<html> 
<head> 
    <title>Cart</title> 
    <link rel='stylesheet' href='css/main.css' /> 
</head> 
<body> 
    <?php 
    $page = 'index.php'; 

    if(isset($_GET['add'])){ 
     $add_id = $_GET['add']; 
     $quantity = mysql_query("SELECT id, quantity FROM products WHERE id='$add_id'"); 
     while($quantity_row = mysql_fetch_assoc($quantity)){ 
      if($quantity_row['quantity'] [email protected]$_SESSION['cart_'.$add_id]){ 
       @$_SESSION['cart_'.$_GET['add']]+='1'; 
       header('Location: index.php'); 
      } 
      else{ 
       header('Location: index.php?err=max'); 
      } 
     } 

    } 

    if(isset($_GET['remove'])){ 
     $_SESSION['cart_'.(int)$_GET['remove']]--; 
     header("Location: index.php"); 
    } 

    if(isset($_GET['delete'])){ 
     $_SESSION['cart_'.(int)$_GET['delete']]='0'; 
     header('Location: index.php'); 
    } 

    function products(){ 
     $get = mysql_query("SELECT id, name, description, price FROM products WHERE quantity > 0 ORDER BY id DESC"); 
     if(mysql_num_rows($get) == 0){ 
      echo "There are no products to display."; 
     } 
     else{ 
      while($get_row = mysql_fetch_assoc($get)){ 
       echo '<p>'.$get_row['name'].'<br />'.$get_row['description'].'<br />$'.$get_row['price'].' <a href="cart.php?add='.$get_row['id'].'">Add</a></p>'; 
      } 
     } 
    } 

    function cart(){ 
     foreach($_SESSION as $name => $value){ 
      if($value>0){ 
       if(substr($name, 0, 5)=='cart_'){ 
        $id = substr($name, 5, strlen($name)-5); 
        $get = mysql_query("SELECT id, name, price FROM products WHERE id='$id'"); 
        while($get_row = mysql_fetch_assoc($get)){ 
         $sub = $get_row['price']*$value; 
         echo $get_row['name'].' x '.$value.' @ $'.number_format($get_row['price'], 2).' = $'.$sub.' <a href="cart.php?add='.$id.'">[+]</a> <a href="cart.php?remove='.$id.'">[-]</a> <a href="cart.php?delete='.$id.'">[Delete]</a>'; 
        } 
       } 
       $total += $sub; 
      } 
     } 
     echo '<br />'.$total; 
    } 

    ?> 
</body>

在此先感谢您的帮助。在不久的将来我可能需要更多的帮助。

来源

2013-02-15 WorldxFree

哦，男孩。您的代码易受SQL注入攻击。我希望你不打算在生产中使用它。你也应该停止使用'mysql_'函数。他们不再被维护[并且被正式弃用]（http://j.mp/XqV7Lp）。看到[**红框**]（http://j.mp/Te9zIL）？学习[*准备的语句*]（http://j.mp/T9hLWi），并使用[PDO]（http://php.net/pdo）或[MySQLi]（http://php.net/ mysqli） - [这篇文章]（http://j.mp/QEx8IB）将帮助你决定哪个。 – Kermit 2013-02-15 22:45:56

哦。感谢您的建议。 – WorldxFree 2013-02-15 22:48:54

查看[谁是Bobby Tables？]（http://bobby-tables.com/）了解更多信息。 – Kermit 2013-02-15 22:49:41

代码试图做的第一次$total+=$sub，$total未定义。

您需要在cart()函数的顶部设置$total：

function cart(){ 
    $total = 0; 
    /// rest of code 
}

来源

2013-02-15 22:44:48

我认为这里的问题是它超出了范围。 – Kermit 2013-02-15 22:51:17

在你的函数购物车（）：

声明变量$total第一。

例如$total = 0 ; ，然后开始递增它$total += $sub ;

来源

2013-02-15 22:48:53 vikingmaster

<?php 
include('inc/connect.php'); 
session_start(); 
?> 
<html> 
<head> 
    <title>Cart</title> 
    <link rel='stylesheet' href='css/main.css' /> 
</head> 
<body> 
    <?php 
    $page = 'index.php'; 

    if(isset($_GET['add'])){ 
     $add_id = $_GET['add']; 
     $quantity = mysql_query("SELECT id, quantity FROM products WHERE id='$add_id'"); 
     while($quantity_row = mysql_fetch_assoc($quantity)){ 
      if($quantity_row['quantity'] [email protected]$_SESSION['cart_'.$add_id]){ 
       @$_SESSION['cart_'.$_GET['add']]+='1'; 
       header('Location: index.php'); 
      } 
      else{ 
       header('Location: index.php?err=max'); 
      } 
     } 

    } 

    if(isset($_GET['remove'])){ 
     $_SESSION['cart_'.(int)$_GET['remove']]--; 
     header("Location: index.php"); 
    } 

    if(isset($_GET['delete'])){ 
     $_SESSION['cart_'.(int)$_GET['delete']]='0'; 
     header('Location: index.php'); 
    } 

    function products(){ 
     $get = mysql_query("SELECT id, name, description, price FROM products WHERE quantity > 0 ORDER BY id DESC"); 
     if(mysql_num_rows($get) == 0){ 
      echo "There are no products to display."; 
     } 
     else{ 
      while($get_row = mysql_fetch_assoc($get)){ 
       echo '<p>'.$get_row['name'].'<br />'.$get_row['description'].'<br />$'.$get_row['price'].' <a href="cart.php?add='.$get_row['id'].'">Add</a></p>'; 
      } 
     } 
    } 

    function cart(){ 
    $total = 0; 
     foreach($_SESSION as $name => $value){ 
      if($value>0){ 
       if(substr($name, 0, 5)=='cart_'){ 
        $id = substr($name, 5, strlen($name)-5); 
        $get = mysql_query("SELECT id, name, price FROM products WHERE id='$id'"); 
        while($get_row = mysql_fetch_assoc($get)){ 
         $sub = $get_row['price']*$value; 
         echo $get_row['name'].' x '.$value.' @ $'.number_format($get_row['price'], 2).' = $'.$sub.' <a href="cart.php?add='.$id.'">[+]</a> <a href="cart.php?remove='.$id.'">[-]</a> <a href="cart.php?delete='.$id.'">[Delete]</a>'; 
        } 
       } 
       $total += $sub; 
      } 
     } 
     echo '<br />'.$total; 
    } 

    ?> 
</body>

修正了你的代码。

来源

2013-02-16 06:53:14 VladHQ

PHP代码中未定义的索引？

回答

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