Themes and Variations
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abstraction -- the object metaphor
modeling -- understanding structure and behavior
software architecture -- mastering complexity
frameworks -- patterns for problem solving
components -- scalable software
Postacademische Cursus Informatie Technologie
vrije Universiteit
amsterdam
Object Terminology
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objects -- packet containing data and procedures
methods -- deliver service
message -- request to execute a method
class -- template for creating objects
instance -- an object that belongs to a class
encapsulation -- information hiding by objects
inheritance -- allowing the reuse of class spec.s class
hierarchy -- tree structure inheritance relations
polymorphism -- to hide different implementations
Postacademische Cursus Informatie Technologie
vrije Universiteit
amsterdam
Features of OOP
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information hiding: state, autonomous behavior
data abstraction: emphasis on what rather than how
dynamic binding: binding at runtime,
polymorphism , virtual
inheritance: incremental changes (specialization), reusability
Postacademische Cursus Informatie Technologie
vrije Universiteit
amsterdam
functions
Benefits of OOP
• OO = encapsulation + inheritance
• modularity -- autonomous entities, cooperation through exchanges of
messages
• deferred commitment -- the internal workings of an object can be redefined
without changing other parts of the system
• reusability -- refining classes through inheritance
• naturalness -- object-oriented analysis/design, modeling
Postacademische Cursus Informatie Technologie
vrije Universiteit
amsterdam