¥Organized
in a strict hierarchy with the universal type Object at
the top.
¥Every
class C except
Object has
an immediate superclass, which is the parent of C
in the hierarchy. In a class definition (like our Entry example), the default
superclass is Object.
¥ A descendant in the class hierarchy is
called a subclass. B is a subclass of A iff A is
a superclass of B. Entry is a subclass of Object; Object
is a superclass of Entry.