This macro illustrates how to return objects. As it happens, this macro does nothing. But if you want to return an object, the assignment statement must use "Set".

The geometric mean of two numbers is the square root of the product of the two numbers. This function macro implements it. Notice the choices of function names and argument names. Names can be any string of alphanumeric characters and underscores, starting with letters. Case doesn't matter. In our example, we've chose names that are designed to make the macro easy to understand, without the need for extensive commenting. Managers of groups of people who make spreadsheet models should ensure that function and variable names are chosen with these factors in mind.

Here's an implementation of the depreciation schedule generator that supports the Ripple Principle. It's analogous to what we did in the examples for Session 8. It uses Caller, a property of the Application object that holds the cell that invoked the function. It also uses Column, a property of a cell object. Both of these property invocations illustrate how VBA uses postfix notation to access properties of objects. To test your understanding of Caller, write a worksheet function that returns twice the value of the cell to the right of the caller.