given: The floor()and ceil()methods take only doubles. There are no overloaded methods for integral numbers, because the methods would just end up returning the integral numbers they were passed. The whole point of floor()and ceil()is to convert floating-point numbers (doubles), to integers, based on the rules of the methods. It may seem strange (it does to us) that the integer values are returned in a double sized container, but don�t let that throw you.
what the author is trying to say.please help since i don't get. simple example would be very helpful.