FIT3077 Lecture Notes - Lecture 4: Abstract Factory Pattern
22 Jun 2018
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Department
Course
Professor
Design Patterns
What is a Pattern?
●Each paern describes a problem which occurs frequently in the environment
●Effect paerns provide soluon that are used again and again
A design paern is:
●Smart : elegant soluon not obvious to a novice
●Generic : not dependent upon a system, programming language or applicaon domain
●Well-Proven : been defined from real OO systems
●Simple : quite small, involving only a handful of classes
●Reuseable : easy to reuse
●Object-Oriented : built with OO mechanisms such as classes , objects, generalisaon and
polymorphism
A design paern has:
●Pattern Name : a handle we can use to describe a design problem, its soluon and
consequences
●The problem: describes when to apply the paern
●The solution: describes the elements which make up the soluon and their relaonships
●The consequences: the results and tradeoffs of using the design paern
Categorising Design Patterns
Purpose
●Creational : concern the process of object creaon
●Structural : deal with the composion of classes and objects
●Behavioural : characterise the way in which classes or objects interact and distribute
responsibility
Scope
●Class :
○Concerned with classes
○Relaonships between classes and their subclasses
●Object
○Concerned with object relaonships
○More dynamic and can change at run-me
Document Summary
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