Cart items quantity logic
The idea of the
qty property is that rather than re-adding a product to the cart each time the
addToCart method is called on the same product, we instead just increment the
Does that make sense? If not, stick with me and I'm sure the penny will drop.
To check if an item is already in the cart, we're going to iterate the cart array items and check their
id to see if we get a match.