An
object class is a factory
for producing objects. An object class creates objects (instances) and provides
methods that these objects can use. An object acquires the instance methods
of the class to which it belongs at the time of its creation. If a class gains
additional methods, objects created before the definition of these methods
do not acquire the new or changed methods.
The instance variables within an object are created on demand whenever a method
EXPOSEs an object variable. The class creates the object instance, defines the methods
the object has, and the object instance completes the job of constructing the object.
