Why does Math.floor return a double?

Question

Official Javadoc says that Math.floor() returns a double that is \"equal to a mathematical integer\", but then why shouldn\'t it return an in

Answer 1

It's for precision. The double data-type has a 53 bit mantissa. Among other things that means that a double can represent all whole up to 2^53 without precision loss.

If you store such a large number in an integer you will get an overflow. Integers only have 32 bits.

Returning the integer as a double is the right thing to do here because it offers a much wider usefull number-range than a integer could.