$49.99
private function getProductInfo(int $productId, array $fallbackData = []): array addcartphp num high quality
// ❌ BAD – Don't store product details $_SESSION['cart'][$productId] = [ 'name' => 'T-Shirt', 'price' => 29.99, 'image' => '/img/tshirt.jpg', 'description' => 'A comfortable cotton t-shirt...', // This data belongs in the database! ]; | | num exceeds stock limit | Reject,
| Edge Case | Expected Behaviour | |-----------|--------------------| | num is 0 or negative | Reject, show error, do not add. | | num is not a number (e.g., “abc”) | Validation fails, friendly error. | | num exceeds stock limit | Reject, inform user of available stock. | | Product ID does not exist | Reject, do not add to cart. | | CSRF token missing or wrong | Reject request entirely. | | User adds same product twice | Quantity updates (not duplicate item). | | Quantity update via cart page | Validate each new quantity individually. | | Session expired | Cart resets gracefully – inform user. | | JavaScript disabled | Fallback to standard HTTP POST works. | | | User adds same product twice |