Hi,

We have some helpers in the Variant class:

Variant.getDimension() (delegates to MultiDimensionArrayUtils.getDimension(class), returns 0 if scalar)
Variant.getArrayDimensions() (delegates to MultiDimensionArrayUtils.getArrayLengths(value), return dimensions in array with length of dimensions or 0 if scalar)

It should be noted that apparently these wont work for null value (results NPE; could probably be improved in a future version), thus please check that first.

This is to say, you only know after you have Read it. As for Writing, it shouldn’t need to be the same dimension, if ValueRank allows (what will actually happen would be server-specific though, but spec-wise any of them should like work).

P.S.
Also I would guess most of the time it will be a scalar, since -2 is the default (it has to be) in the basic VariableTypes, thus an instantiation of those would result in -2 unless changed after that.