Design an Online Shopping Cart
Strategy PatternFactory PatternObserver Pattern
Design an online shopping cart system that allows customers to add items to their cart, update quantities, apply discounts and coupons, calculate totals (subtotal, tax, shipping, final total), and persist cart state. The system should handle multiple cart items with the same product, validate inventory before checkout, and support various discount strategies and shipping calculations.
What You'll Build
- Customers should be able to add products to their cart with a specified quantity, aggregating quantities if the same product is added multiple times.
- Customers should be able to remove items from their cart completely.
- Customers should be able to update the quantity of items already in their cart.
- The system should validate product inventory availability when adding items to cart and prevent adding more than available stock.
- The system should support applying different discount strategies (percentage-based, fixed amount, buy-X-get-Y, category-based) using the Strategy Pattern.
- ...and more
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Design Patterns
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