MyDaysInMonth Example

This example shows how to return an array of numbers from an add-in function.

// Function:    MyDaysInMonth
// Returns:     LPXLOPER
// Description: Returns an array of all the days in a given month

//{{XLP_SRC(MyDaysInMonth)
    // NOTE - the FunctionWizard will add and remove mapping code here.
    //    DO NOT EDIT what you see in these blocks of generated code!
IMPLEMENT_XLLFN2(MyDaysInMonth, "RH", "MyDaysInMonth", "Month", 
    "User Defined", "Returns an array of all the days in a given"
    " month", "Month number (1-12)\000", "\0", 1)

extern "C" __declspec( dllexport )
LPXLOPER MyDaysInMonth(USHORT usMonth)
{
    CXlOper xloResult;
//}}XLP_SRC

    if ( usMonth < 1 || usMonth > 12 )
        xloResult = xlerrValue;
    else
    {
        // How many days in the month ?
        int cDays;
        switch ( usMonth ) {
        case 2:
            cDays = 28;
            break;
        case 4: case 6: case 9: case 11:
            cDays = 30;
            break;
        default:
            cDays = 31;
            break;
        }
        
        // Allocate and fill array
        double* adDays = new double[cDays];
        for ( int i = 0; i < cDays; i++ )
            adDays[i] = (double)(i + 1);
        
        // Apply to xloResult
        xloResult.FromDoubleArray(adDays, cDays);

        // Clean up array
        delete[] adDays;
    }

    return xloResult.Ret();
}

Uses

CXlOper::FromDoubleArray