C / C++ / MFC

<br />
// This function will round a number upwards if it's modulus is greater<br />
// than or equal to 0.5 or round it down if it is less than 0.5<br />
double Round(double dVal)<br />
{<br />
	double dRemainder = fabs(fmod(dVal, 1) * (int)10);<br />
	<br />
	if (dVal > 0)<br />
	{<br />
		if (dRemainder >= (int)5)<br />
			return ceil(dVal);<br />
<br />
		return floor(dVal);<br />
	}<br />
<br />
	if (dRemainder >= (int)5)	// Negative numbers require special treatment<br />
		return floor(dVal);<br />
<br />
	return ceil(dVal);<br />
}<br />
<br />
<br />
//	Round to a specified number of decimal places<br />
double Round(double dVal, UINT nDecPlaces)<br />
{<br />
	double dFactor = pow(10.0, (double)nDecPlaces);<br />
	return ( Round( dVal * dFactor) / dFactor);<br />
}<br />

int Rounder(double dValue)
{
    char sBuf[64];
    // sprintf does the rounding for you
    sprintf(sBuf, "%0.lf", dValue);
    return atoi(sBuf);  
}

double Rounder(double dValue, int nDigits)
{
    char sBuf[64];
    // sprintf does the rounding for you to the number of digits you want
    sprintf(sBuf, "%0.*lf", nDigits, dValue);
    return atof(sBuf);
}

int RoundUp(double dValue)
{
    return Rounder(dValue + 0.5);
}

int RoundDown(dowble dValue)
{
    return Rounder(dValue - 0.5);
}