自动递增数组索引（PHP）

只是搜索了一下，找不到一个答案合适的问题。我试图在数组的末尾添加一个product_id，有些时候每次添加某个内容时，它也会添加到数组中。目前，每次我添加产品id时，它都会替换以前存在的内容。我得到的只是数组[0]中的一个product_id。下面是我将添加到数组中的代码部分。然后我使用

print_r($order);

显示数组中的内容

$order = array();

switch ($action)
    {

    // Add

case "add":

$order[] = $product_id;
        break;
        }

以下是页面中的全部代码，减去一些MySQL内容

include 'connection.php';

if (isset($_GET['action']))
    {
    $action = $_GET['action']; //Get's action from the URL
    }

if (isset($_GET['product_id']))
    {
    $product_id = $_GET['product_id']; //the action from the URL
    }

// if there is an product_id and that product_id doesn't exist display an error message



if ($product_id && !productExists($product_id))
    {
    die("Error. Product Doesn't Exist");
    }

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

    // Add

case "add":

$order[] = $product_id;

    if (isset($_SESSION['user']))
        {
        $productadd = sprintf("INSERT INTO tbl_basket (customer_id, product_id, basket_status) VALUES ('" . $_SESSION['user'] . "','$product_id','basket')");
        mysql_query($productadd);
        break;
        }
      else
        {

        $productadd = sprintf("INSERT INTO tbl_basket (customer_id, product_id, basket_status, user_type) VALUES ('" . $_SESSION['guestuser'] . "','$product_id','basket', 'guest')");
        mysql_query($productadd);
        break;
        }

    // Remove

case "remove":
    if (isset($_SESSION['user']))
        {
        $productremove = sprintf("DELETE FROM tbl_basket WHERE customer_id = '" . $_SESSION['user'] . "' AND product_id = '$product_id'");
        mysql_query($productremove);
        break;
        }
      else
        {
        $productremove = sprintf("DELETE FROM tbl_basket WHERE customer_id = '" . $_SESSION['guestuser'] . "' AND product_id = '$product_id'");
        mysql_query($productremove);
        break;
        }

    // Empty

case "empty":
    if (isset($_SESSION['user']))
        {
        $empty = sprintf("DELETE FROM tbl_basket WHERE customer_id = '" . $_SESSION['user'] . "' AND order_status = 'basket'");
        mysql_query($empty);
        break;
        }
      else
        {
        $empty = sprintf("DELETE FROM tbl_basket WHERE customer_id = '" . $_SESSION['user'] . "' AND order_status = 'basket'");
        mysql_query($empty);
        break;
        }
    }

if (isset($_SESSION['user']))
    {
    $result = mysql_query("SELECT * FROM tbl_basket a INNER JOIN tbl_products b ON a.product_id = b.product_id WHERE a.customer_id = '" . $_SESSION['user'] . "'");
    }
  else
    {
    $result = mysql_query("SELECT * FROM tbl_basket a INNER JOIN tbl_products b ON a.product_id = b.product_id WHERE a.customer_id = '" . $_SESSION['guestuser'] . "'");
    }

---

执行

$order=array（）操作时，可以清除
$order
中以前的值

只需删除该行并
$order[]=$product\u id将向数组中添加另一项。
似乎是可变范围的问题。请提供更多代码。如果有一个循环-显示它。我已经用更多的代码更新了这个问题。我认为这与每次重新初始化数组有关。这仍然会替换所有内容。因此，我目前拥有的数组的唯一代码是$order[]=$product\u id@user3521635在添加到数组之前检查数组，以查看其中包含的内容。
$order = array();

switch ($action)
    {

    // Add

case "add":

$order[] = $product_id;
        break;
        }