Is there a way to check if a variable is a whole number? C++

Question

I need to check if a variable is a whole number, say I have the code:

double foobar = 3;
//Pseudocode
if (foobar == whole)
    cout << "It's whole";
else
    cout << "Not whole";

How would I do this?

Answer 1

Assuming foobar is in fact a floating point value, you could round it and compare that to the number itself:

if (floor(foobar) == foobar)
    cout << "It's whole";
else
    cout << "Not whole";

Answer 2

You are using int so it will always be a "whole" number. But in case you are using a double then you can do something like this

double foobar = something;
if(foobar == static_cast<int>(foobar))
   return true;
else
   return false;