Passing Parameters to Functions

When you create your own functions, it is often helpful to pass parameters to the function. These parameters can be used either as data that you want the function to act upon, or as settings used to control how the function does its work. How you pass parameters to functions is illustrated in the following macros:

Sub Macro1()
    A = 12.3456
    Status.Bar = A & "     " & Round(A)
End Sub

Function Round(X)
    Round = Int(X + 0.5)
End Function

This simple macro defines a number, and then prints it and the result of passing the number to the Round function; the output is 12.3456 and 12. Notice that the parameter should be passed to the function within parentheses. Also notice that the function does not use the same variable name as it was passed. This is because VBA reassigns the value of X (what the function needs) so it matches the value of A (what the program is passing to the function). The important thing to remember in passing parameters to functions is that your program must pass the same number of parameters as the function expects, and the parameters must be of matching types and in the proper order.