Why does ceiling in .NET return a Double and not an integer?

Question

As explained here, Math.Ceiling returns: "The smallest integral value that is greater than or equal to a". But later it says: "Note that this method returns a Double type instead of an integral type." I'm just wondering why?

Answer 1

Because a double has a much bigger maximum value than an integer supports.

Asking for the ceiling on a double that has a value greater than Int32.MaxValue (or even Int64.MaxValue) would not be possible if it returned an integer.

Answer 2

I think the purpose of that 'note' is to make sure people aren't led astray by the phrase 'integral value' into thinking that the return value is necessarily of an integer type. As other answers point out, not all integral values can be stored in integer-y types.