比较两个数组的问题

Question

I'm trying to compare the content of 2 arrays, basically I'm using a shopping cart and I need to check the prices of submitted forms against a database, the problem is when I have one incorrect price in the shopping cart it gives me an error message but when I have 1 correct price and 1 incorrect it continues with the checkout, I don't know what I'm doing wrong any help would be appreciated.

 foreach ($cart->get_contents() as $item)
    {
    $item_id    = $item['id'];
    $item_name  = $item['name'];
    $item_price = $item['price'];
    $item_qty   = $item['qty'];

$connection = mysql_connect($dbhost,$dbuser,$dbpass) or die("Error connecting to mysql");
mysql_select_db($dbname);

$query = "select * from products where product_name = '$item_name'";

$result = mysql_query($query);
if (!$result) {
    echo mysql_error();
}

while ($row = mysql_fetch_assoc($result)) {
    $sql_price[] = $row['product_price'];
    $qty[] = $row['product_qty'];
    $name = $row['product_name'];
}
foreach($sql_price as $price) {
    $price = $price;
    if ($price !== $item_price) {
        $valid_prices = false;
    }else{


        $valid_prices = true;
    }
    }
    }

     if ($valid_prices !== true)
    {
    // KILL THE SCRIPT
    die($jcart['text']['checkout_error']);
    }

Answer 1

The problem is you marking the cart entry as valid if the last array element of $sql_price equals $item_price.

Rewrite the loop as:

$valid_prices = true;

foreach($sql_price as $price) {
        $price = $price;
        if ($price !== $item_price) {
                $valid_prices = false;
        }
}

To prevent extra iterating, add a break in the inner if to stop the loop after finding an invalid price.

Or even this:

$valid_prices = (array_search($price, $sql_price) !== false);

You can have MySQL do all your work for you, even:

$query = 'select 1 from products where product_name = "' . mysql_real_escape_string($item_name) . '" and product_price = ' . (int)$item_price;

$result = mysql_query($query);
if (!$result) {
        echo mysql_error();
}

if (mysql_num_rows($result) > 0) {
        $valid_prices = true;
        echo 'price is good!';
} else {
        $valid_prices = bad;
        echo 'price is bad!';
}