how to know size of class

I am using a toolbox that makes use of .Net assembly but unfortunately I am not at all familiar with this so I hope that you can help me out. It is not so difficult what I want to do but I cannot figure it out

so I have a class (e.g. X) for which I have asked for the methods that I can apply (e.g. GetStaticData)

Now I want to know how many staticData there are in the class because I need to perform a for-loop to get all the data

for ii = 1: numberStaticDatas
   extracted(ii) = X.getStaticData(ii);
end

So how to I know numberStaticDatas when this is not defined in the class as such? If I try to just use a randomly large number it works up to the index is out of bound, so I would like to know in advance what this number is

The item number is out of range. (F_FAIL_ILLEGEAL_ITEM)