If you need differend objects, then you best have accces to familys. Looping trough families is the same as looping truough instances ...
Pick a group of objects.
Pick the array
Array > set size > width = object.count - 1, Height = amount of variables you need to store
Z must be at least 1 .. Zero will make an unusable array
System > For > name = "index", start = 0, end = object.count - 1 (because it is zero based)
Now the loopcounter is the expression loopindex("index"), we use that as IID of an object and as X index in the array.
You need Y indexes for the variables.
System > Pick nth instance > object = object, instance = loopindex("index")
Array > set at XY > X = loopindex("index") , Y =0, value = Object.X
Array > set at XY > X = loopindex("index") , Y =1, value = Object.Y