Add-cart.php Num Best

In web development, particularly in PHP-based e-commerce systems, add-cart.php (or similar filenames like cart_update.php or handlecard.php) serves as the backend controller responsible for adding items to a user's virtual shopping cart. Core Functionality

Key Features Implemented:

Quantity handling - Supports adding specific quantities (num parameter)
Session-based cart - Persists across pages
Input validation - Prevents invalid product IDs and quantities
Stock checking - Optional inventory validation
AJAX support - Adds items without page refresh
Cart management - Update/remove items from cart
Error handling - User-friendly error messages
Cart totals - Calculates item count and total price

// Secure Code $quantity = intval($_GET['num']);

Financial fraud (negative pricing)
Inventory destruction
SQL/NoSQL injection
Log forging
Session hijacking

// Verify product exists and is in stock

Sanitize Inputs: Retrieve the product ID and the "num" (quantity) from $_GET or $_POST. Use type casting (e.g., (int)) to prevent injection attacks. add-cart.php num

Malicious Request: add-cart.php?id=100&num=-999 Quantity handling - Supports adding specific quantities (