Private and shared data in object-oriented programming

Abstract

In a typical object-oriented system, there are two kind of variables: those which are private to instances(objects) and those which are shared by all instances of a class. Variables may also be declared in some object-oriented languages as private, public, or subtype visible which affects the access to the data. However we know of no object-oriented programming which allows data(variables) to be declared as private for specific methods only. The purpose of this thesis is to propose a solution to the problems of implementing and maintaining both shared and private data at various levels within an object-oriented environment.