Fatal error: Declaration of .. must be compatible with .. PHP

Question

I\'m getting the following error:

Fatal error: Declaration of Shoppingcart::addToCart() must be compatible with that of Ishoppingcart::addToCart() in klassen         


        

Answer 1

Interface Ishoppingcart seems to define addToShoppingCart without parameters, but class Shoppingcart defines the same function taking Product as a parameter. I suppose the method in the interface should take Product as a parameter as well.