The "add-cart.php" script is usually a server-side script written in PHP, a popular scripting language used for web development. When a customer decides to add a product to their shopping cart, they click on an "Add to Cart" button next to the product. This action triggers the "add-cart.php" script, which then performs several key functions:
// Add to cart logic if (isset($_SESSION['cart'][$product_id])) // Product exists, update quantity $_SESSION['cart'][$product_id] += $quantity; else // New product, add to cart $_SESSION['cart'][$product_id] = $quantity; add-cart.php num
The script typically manages the "Add to Cart" action by performing the following steps: The "add-cart
$productId = filter_input(INPUT_POST, 'product_id', FILTER_VALIDATE_INT); $quantity = filter_input(INPUT_POST, 'quantity', FILTER_VALIDATE_INT); update quantity $_SESSION['cart'][$product_id] += $quantity
The num parameter (often named qty , quantity , or count ) tells the backend how many units of a product to place into the session array.
<?php session_start();