Thread: Most Efficient Way to Check a Variable Is A Whole Number

Hi,

I have a question. Say you have a variable of type double, and you want to check if it is a whole number or not. What is the most efficient way to do this? At present I am doing something like this, but it doesn't seem very efficient.

Code:

#include <iostream>
using namespace std;

int main()
{
    double a_dbl = 3.5;
    int a_int = static_cast<int>(a_dbl);

    if (a_dbl == a_int)
        cout << "a_dbl is a whole number";
    else 
        cout << "a_dbl is not a whole number";
}

Thanks guys.