It is much more efficient to save a single ArrayList to disc than it is to save a series
of individual objects. Placing a series of objects into a single ArrayList is a very neat
way of packaging and transferring our objects. This technique carries another significant advantage:
we shall have some form of random access , via the ArrayList
class’s get method (albeit based on knowing each element’s position within the
ArrayList ). Without this, we have the considerable disadvantage of being restricted
to serial access only.