This topic shows you how to return a 1-dimensional array to Excel. The example is a very simple function for sorting numeric arrays in ascending order.

Use the Function Wizard to create a new function with these properties:

Name:	SORTVECTOR
Return type:	CXlOper
Category:	Lookup & Reference
Description:	Sort a vector of numbers in ascending order

Add a single vector argument with the following properties:

Type:	Double[]
Name:	Vector
Description:	Unsorted vector of numbers

Press OK to return to Visual Studio.

Add code so that your add-in function looks like this:

CXlOper* SORTVECTOR_Impl(CXlOper& xloResult, const CXlOper* Vector_op)
{
    // Input buffers 
    std::vector<double> Vector;
    // Validate and translate inputs
    XlReadVector(*Vector_op, Vector, L"Vector", XLA_TRUNC_ONEMPTY|
        XLA_TRUNC_ONBLANK);
    // End of generated code 
//}}XLP_SRC 
 
    // Use STL algorithm to sort input                   
    std::sort(Vector.begin(), Vector.end());             
    // Copy the sorted vector to xloResult               
    xloResult = Vector;                                  
 
    return xloResult.Ret();
}

Yet another overload of the CXlOper assignment operator is used to copy the STL vector into xloResult:

xloResult = Vector;

The operator creates an array of values within xloResult and populates it with the values in Vector.

This is one of the most pleasingly simple add-in functions in this tutorial. It is not necessarily very useful - a better implementation would sort a 2-dimensional array by a given column or columns, in ascending and descending order - but it is very short, and does a surprising amount of work with only two lines of hand-written code.

Next: Array formulae in Excel >>