On the slicing: You can clone the whole array far easier:
local a2:int[] = a1[..]
But your point on that is right. As an array is a type inherited from :Object, assigning it to something only changes the reference of the array, not its content.
local a2:int[] = a1[..]
But your point on that is right. As an array is a type inherited from :Object, assigning it to something only changes the reference of the array, not its content.