How to get amount of serialized bytes representing a Java object?

Question

What syntax would I use to get the number of bytes representing a string and compare them to the number of bytes representing an ArrayList holding that string, for

Answer 1

You can serialise each object into arrays and compare the length of each array. This is not very accurate, in the general case, but often gives a good approximation.

Have a look at ObjectOutputStream (which can be used to serialise an object and turn it into Bytes) and ByteArrayOutputStream (which can be used to hold the serialised bytes).