Things used to be so simple, back around … oh, AutoCAD 2011. ARRAY was unequivocally a modifying command, just like COPY or ROTATE. You filled in values in a dialog box, and after a bit of tweaking, you ended up with multiple copies of the source objects, neatly arranged in geometric patterns: either in evenly spaced rows and columns, or evenly distributed radially about a center point. Then Autodesk's programmers decided old-fashioned arrays weren't enough. They took the old ARRAY command into the lab, wired electrodes to its brain and threw the switch — and up rose the new super ARRAY!
The results of using the new ARRAY command are so different from those you got in previous releases that I really wish they'd given it a new name. I'm going to do my best to clarify the muddy waters, so here's the terminology I'm using in this book: