Thread: Problem with rounding floating points

Code:

int convMinutes(double x)
{
    int mins = static_cast<int>(x) * 60;
    cout << x - static_cast<int>(x);
    mins = (x - static_cast<int>(x)) * 100;
    cout << mins;
    
    return mins;
}

The problem is to take a floating point number (x) and look at it as if it's a time input in format HH.MM. If I enter, say 12.59 as x, the first cout outputs .59. The second one outputs 58. .59 * 100 is not 58. I can only assume some internal rounding is messing up my conversion.

Any insights, ideas, would be much appreciated.

>No, but .589999999999999999 cast to an int and THEN multiplied by 100 is 58.
Actually it's more like 0.