>Does anyone know of a book, course, or tutorial that will teach me how to handle deeper concepts of array handling, something beyond the regular 2-dimensional arrays? My client has one set of arrays that are nested to 10 levels deep. I know that someone on here will say, "Oh, that's a piece of cake (or easy)! An array is just an array."

Can you give us an idea of what it's used for, and what you need to do? Is it used in support of something like a treeview? Or is there advanced math being used e.g. matrix operations?

I don't know how much of this you already know but it may be useful for others:

If you're working in VFP you have DIMENSION to create arrays, then you have to know the syntax for addressing array elements. VFP arrays are one-based (as opposed to many other languages where they are zero-based).

There are various primitive functions available e.g.

ACOPY()
ADEL()
AELEMENT()
AINS()
ASORT()
ASUBSCRIPT()

VFP supports only 1- or 2-dimensional arrays. By "nesting" I suspect you've got a situation where the elements of a given array are themselves arrays, and so forth down as deep as 10 levels.

If there's existing code, hopefully it includes some more advanced user-defined functions that let you do things like traverse the links/nesting levels. Code like that is often recursive (or it should be) which tends to be tricky and requires great care in maintaining or enhancing.

As a side note, if you're working with something like a treeview, rather than using nested arrays you can use a single data table (i.e. DBF) and implement a linked list. Processing usually requires writing your own (usually recursive) UDFs. However, depending on what you want to do there may be the option to use dBASE-style ISAM processing (SCAN, GOTO, SKIP etc.) or even the SQL engine. If you're familiar with Fox you may find this approach more intuitive than using arrays.