tailieunhanh - Lecture Object-oriented software engineering - Chapter 2: Review of object orientation

In this chapter, you learned to: What is object orientation? Classes and objects; instance variables; methods, operations and polymorphism; organizing classes into inheritance hierarchies; the effect of inheritance hierarchies on polymorphism and variable declarations;.and another content. | Object-Oriented Software Engineering Practical Software Development using UML and Java Chapter 2: Review of Object Orientation © Lethbridge/Laganière 2005 Chapter 2: Review of Object Orientation What is Object Orientation? Procedural paradigm: Software is organized around the notion of procedures Procedural abstraction Works as long as the data is simple Adding data abstractions Groups together the pieces of data that describe some entity Helps reduce the system’s complexity. Such as Records and structures Object oriented paradigm: Organizing procedural abstractions in the context of data abstractions © Lethbridge/Laganière 2005 Chapter 2: Review of Object Orientation Object Oriented paradigm An approach to the solution of problems in which all computations are performed in the context of objects. The objects are instances of classes, which: are data abstractions contain procedural abstractions that operate on the objects A running program can be seen as a . | Object-Oriented Software Engineering Practical Software Development using UML and Java Chapter 2: Review of Object Orientation © Lethbridge/Laganière 2005 Chapter 2: Review of Object Orientation What is Object Orientation? Procedural paradigm: Software is organized around the notion of procedures Procedural abstraction Works as long as the data is simple Adding data abstractions Groups together the pieces of data that describe some entity Helps reduce the system’s complexity. Such as Records and structures Object oriented paradigm: Organizing procedural abstractions in the context of data abstractions © Lethbridge/Laganière 2005 Chapter 2: Review of Object Orientation Object Oriented paradigm An approach to the solution of problems in which all computations are performed in the context of objects. The objects are instances of classes, which: are data abstractions contain procedural abstractions that operate on the objects A running program can be seen as a collection of objects collaborating to perform a given task © Lethbridge/Laganière 2005 Chapter 2: Review of Object Orientation A View of the Two paradigms See in Umple © Lethbridge/Laganière 2005 Chapter 2: Review of Object Orientation Classes and Objects Object A chunk of structured data in a running software system Has properties Represent its state Has behaviour How it acts and reacts May simulate the behaviour of an object in the real world © Lethbridge/Laganière 2005 Chapter 2: Review of Object Orientation Objects © Lethbridge/Laganière 2005 Chapter 2: Review of Object Orientation Classes A class: A unit of abstraction in an object oriented (OO) program Represents similar objects Its instances A kind of software module Describes its instances’ structure (properties) Contains methods to implement their behaviour © Lethbridge/Laganière 2005 Chapter 2: Review of Object Orientation Is Something a Class or an Instance? Something should be a class if