Addcartphp — Num High Quality

// 2. Get and validate product ID $productId = filter_input(INPUT_POST, 'product_id', FILTER_VALIDATE_INT); if (!$productId || $productId <= 0) $_SESSION['error'] = 'Invalid product.'; header('Location: shop.php'); exit;

-- Products table CREATE TABLE `products` ( `id` INT(11) UNSIGNED AUTO_INCREMENT PRIMARY KEY, `sku` VARCHAR(50) NOT NULL, `name` VARCHAR(255) NOT NULL, `price` DECIMAL(10,2) NOT NULL, `stock_quantity` INT(11) NOT NULL DEFAULT 0, `status` TINYINT(1) DEFAULT 1, INDEX `idx_stock` (`stock_quantity`, `status`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

$_SESSION['cart'][$cartKey]['quantity'] = $newQuantity;

High quality means covering scenarios that break naive implementations. Test the following: addcartphp num high quality

public function getTotal() $total = 0; foreach ($this->items as $item) $total += $item['price'] * $item['quantity'];

Check if the requested quantity complies with business limitations (e.g., maximum order limits per customer, current inventory levels).

Then update_cart.php :

<?php function getCartTotal() if (session_status() === PHP_SESSION_NONE) session_start();

return ['success' => true, 'cart_count' => count($_SESSION['cart'])];

To make the site feel "high quality," never refresh the page when adding a product. Use JavaScript (AJAX) to handle the num (quantity) input. javascript Then update_cart

// Initialize cart if needed if (!isset($_SESSION['cart'])) $_SESSION['cart'] = [];

To transition from a vulnerable system to a high-quality, enterprise-grade shopping cart backend, you must apply the principle of . Your code should operate on three rigid rules:

$cart_items = []; $total = 0;