A number is whole if it is a non-negative integer with no decimal part. So
233494.0 are whole, while
233494.999 are not.
A floating-point number in the default base/encoding of your language.
Note that if your language only supports decimal precision to, say, 8 places,
1.000000002 can be considered whole.
Input and output may be done via any standard I/O methods.
Input -> Output 332 -> true 33.2 -> false 128239847 -> true 0.128239847 -> false 0 -> true 0.000000000 -> true 1.111111111 -> false -3.1415926 -> false -3 -> false
As with code-golf, the shortest submission wins. Good luck!