By simple classes i mean classes/structures that do not contain vectors, stacks, linked list or any other variable length data structures.

1. If we have a class with some simple double, long, int,... fields, does serialized sizes of different instances of this class depend on the value of these fields? (e.g depending on number of meaningful bits, in case of ignoring left 0 bits to save space)
2. How do strings affect size of serialized data?