Sunday, November 7, 2010

Structured vs. Object Oriented Paradigm

According to K. Hopkins (2001) structured, orimperative, programming paradigm are build three fundamental constructs which are sequence, decision and repetition. Brookshear (2007) defines structured programming paradigm as a “programming process to be developed of a sequence of commands that, when followed, manipulate the data to produce the desirable result”. Therefore, it could be summarized as a process of implementing an algorithm as a sequence of commands. Structured programming paradigm suffered from a number of crucial issues such as memory leaks and deep hierarchies.
Object oriented programming paradigm decompose the system into a collection of objects each of which is capable of performing functionality related to itself. In addition, objects can interact between themselves to create a complex network of relationships to solve the problem at hand. Software development process using object oriented paradigm described by Mohamed, Ahmed Yakout A.; Hegazy, Abd El Fatah A.; Dawood, Ahmed R. (2010) as a process of orchestrating a data flow between collection of objects each manipulating the data to solve software problem. Those, in turn, allows better re-usage of objects and decoupling between the classes. A book published by Erich Gamma at al. (sometimes called “Gang of Four”) describes describes common programming problems and patterns for solving them allowing re-usage not only of the source code (objects) but re-usage of the design patterns as well.
According to Brookshear (2007), object oriented programming paradigm is based on a key five elements which are class, abstraction, encapsulation, inheritance, and polymorphism.
  • Class defines data object including characteristics such as attributes and methods or operations. For example, class Fish would includes attributes such as eyes, mouth, fins, and will be able to perform the following operations/methods: eat and swim.
  • Inheritance is a technique to described similar yet difference class characteristics. For example, Class Mammals would define attributes such as eyes, mouth and limbs and methods such as eat and walk. Then, class Dog would inherit all attributes and methods of Mammal with addition of specific methods such as bark. This allows software designer to reuse already implemented classes and extend those to solve a specific problem.
  • Abstraction, according to Wikipedia (n.d.) is “the act of representing essential features without including the background details or explanations”.
  • Encapsulation refers to ability of the class to conceal or restrict access to certain internal properties or methods. For example, a method bark could in theory use internal methods to implement the functionality but methods are considered as private (i.e. accessible by the object itself).
  • Polymorphism allows inheriting objects to mutate functionality to suit type-specific behaviour. For example, classes Doberman Pincher and German Shepherd both inheriting class Dog, could override the implementation of the method bark to match the distinct features of that specific bread.
Based on the characteristics of object oriented paradigm, it could be said that it better reflects the human way of thinking due to the fact that each real-world item is represented as object within the software with all relevant concepts (implemented as attributes and methods). On the downside, object oriented programming is usually associated with reduced performances and higher memory consumption due to the fact that each object has to be initiated and destroyed at the end of the object life cycle.
It is also important to note, that emerging software programming paradigms are constantly being developed. For example, aspect oriented that “that seeks new modularization of software systems in order to isolate secondary or supporting functions from the main program's business” (Mohamed, Ahmed Yakout A. at al 2010). According to aspect oriented programming paradigm, similar concepts or aspects such as error handling, logging and catching should be implemented in a separate functional units to solve the issue of code scattering and tangling.


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