At this stage of the book, we have covered most of the fundamentals of programming with VBA, including the use of objects in the Access object model and in the Data Access Object hierarchy. We will now take a look at some of the more sophisticated features of VBA. As such, this chapter is a mixed bag of ideas and techniques that have been either too complex to tackle until now, or that have required knowledge of other features before you could learn about them. We will also discuss in more detail a few items that we've already mentioned in some of the earlier chapters. In effect, we are going to be looking at four separate subject areas under the broad umbrella of advanced programming.
First, we'll take another look at arrays, because there is a lot that we haven't considered yet, such as how VBA distinguishes arrays from variables . Then we'll have a look at some of the more interesting ways that we can pass arguments between VBA procedures. After that, we will be investigating how we can extend the functionality of VBA by using code from Dynamic Link Libraries (DLLs). Finally, we'll look at how we can extend Data Access Objects by adding our own properties to them.
So, the main topics of discussion in this chapter are:
Getting more out of arrays
Passing parameters by reference and by value
Creating custom properties for Data Access Objects