dongwupei7803 2014-05-18 13:51
浏览 121
已采纳

创建并添加到会话

I am creating a shopping cart and having some trouble adding the first item to it. The shopping cart code is below:

switch($action) { //decide what to do 

    case "add":

        $_SESSION['cart'][$Item_ID]++; //add one to the quantity of the product with id $product_id 
    break;

    case "remove":
        $_SESSION['cart'][$Item_ID]--; //remove one from the quantity of the product with id $product_id 
        if($_SESSION['cart'][$Item_ID] == 0) unset($_SESSION['cart'][$Item_ID]); //if the quantity is zero, remove it completely (using the 'unset' function) - otherwise is will show zero, then -1, -2 etc when the user keeps removing items. 
    break;

    case "empty":
        unset($_SESSION['cart'][$Item_ID]); //unset the whole cart, i.e. empty the cart. 
    break;

    case "nothing":
    break;
}

When I add an item for the first time (the first one added to the basket) it gives me these errors

Notice: Undefined index: cart in H:\STUDENT\S0190204\GGJ\Basket.php on line 59 Notice: Undefined index: 1 in H:\STUDENT\S0190204\GGJ\Basket.php on line 59
  • 写回答

1条回答 默认 最新

  • doushan1157 2014-05-18 13:55
    关注

    try this

     case "add":
     if(!isset($_SESSION['cart'][$Item_ID])){
      $_SESSION['cart'][$Item_ID]=0;
     }
      $_SESSION['cart'][$Item_ID]++;
      break;
    

    This should work because when you are gonna try to increment first time $_SESSION['cart'][$item_ID] it is not set

    see this

    $_SESSION['cart'][$Item_ID]++ is equvivalent to

    $_SESSION['cart'][$Item_ID] = $_SESSION['cart'][$Item_ID] + 1;
    

    in the above expression $_SESSION['cart'][$Item_ID] is undefined (on right-hand side of assignment)

    本回答被题主选为最佳回答 , 对您是否有帮助呢?
    评论

报告相同问题?

悬赏问题

  • ¥15 求差集那个函数有问题,有无佬可以解决
  • ¥15 MATLAB动图问题
  • ¥15 【提问】基于Invest的水源涵养
  • ¥20 微信网友居然可以通过vx号找到我绑的手机号
  • ¥15 寻一个支付宝扫码远程授权登录的软件助手app
  • ¥15 解riccati方程组
  • ¥15 display:none;样式在嵌套结构中的已设置了display样式的元素上不起作用?
  • ¥15 使用rabbitMQ 消息队列作为url源进行多线程爬取时,总有几个url没有处理的问题。
  • ¥15 Ubuntu在安装序列比对软件STAR时出现报错如何解决
  • ¥50 树莓派安卓APK系统签名