K&B chapter6 examwatch doubt

[Shiva Mohan]

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.

[Keith Lynn]

What the author is saying is that they don't know why the developers made the output of the floor() and ceil() methods double and not int.

The purpose of floor() is to return the value of the mathematical operation greatest integer, [x].

ceil() is going to return the value of the mathematical operation, [x] + 1.

The author is warning you not to get confused because the output of the methods are double.