Need help understanding how to declare and use a property that is a multidimensional array

I need to declare a class property that’s a two dimensional array but the problem is that the size of one dimension isn’t known until runtime.

How would I declare it in the IDE? “name(-1, -1)” didn’t work and then how do I properly Dim it?

this works in the window, at least in xojo 2029r3.1

Untitled(-1,-1)

resize at runtime

Untitled.ResizeTo(5,5)

I failed to notice that I had typed a period rather than a comma. My bad