Softwear presentation
Download as PPT, PDF•0 likes•181 views
This document discusses object-oriented programming concepts like classes, objects, inheritance, polymorphism, and class hierarchies. It explains that classes define templates for objects, with subclasses inheriting attributes and methods from superclasses. The document also outlines steps for object-oriented development like identifying candidate classes, looking for existing classes in a library, and engineering new classes when needed.
Softwear presentation
- 1. 1
- 2. By: Nabeela Khan Alina Asif Sidra Bibi 2
- 3. Object ◦ encapsulates both data (attributes) and data manipulation functions (called methods, operations, and services) Class ◦ generalized description (template or pattern) that describes a collection of similar objects Super-class ◦ a collection of objects Sub-class ◦ an instance of a class 3
- 4. Class hierarchy ◦ attributes and methods of a super-class are inherited by its sub-classes Messages ◦ the means by which objects exchange information with one another Inheritance ◦ provides a means for allowing sub-classes to reuse existing super-class data and procedures ◦ provides mechanism for propagating changes 4
- 5. Polymorphism ◦ mechanism that allows several objects in an class hierarchy to have different methods with the same name ◦ instances of each sub-class will be free to respond to messages by calling their own version of the method 5
- 6. Build new class from scratch without using inheritance Use inheritance to create new class from existing class contains most of the desired attributes and operations Restructure the class hierarchy so that the required attributes and operations can be inherited by the newly created class 6
- 7. Override some attributes or operations in an existing class and use inheritance to create a new class with (specialized) private versions of these attributes and operations. 7
- 8. Customer communication Planning Risk analysis Engineering construction and analysis Customer evaluation 8
- 9. Identify candidate classes Look-up classes in library Extract classes if available Engineer classes if not available ◦ Object-oriented analysis (OOA) ◦ Object-oriented design (OOD) ◦ Object-oriented programming (OOP) ◦ Object-oriented testing (OOT) Put new classes in library Construct Nth iteration of the system 9
- 10. External Entities ◦ devices or people Things in Problem Domain ◦ Reports, displays, signals Events ◦ completion of some task Roles ◦ manager, engineer, salesperson Organizational Units ◦ divisions, groups, teams Structures ◦ sensors, vehicles, computers 10
- 11. Does object information need to be retained? Does object provide a set of needed services that can change its attributes? Does object have major (important) attributes? Can you identify common attributes for all object instances? Can you identify common operations for all object instances? Is it an external entity that produces or consumes information? 11
- 12. Establish a common process framework (CPF). Use CPF & historic data to eliminate time & effort. Specify products & milestones. Define Q.A. checkpoints. Manage changes. Monitor project. 12
- 13. Contracts completed. Object-Oriented Analysis completed. Object-Oriented Design completed. Object-Oriented Programming completed. Object-Oriented Testing completed. 13
- 14. Number of scenario scripts. Number of key classes. Number of support classes. (# key classes)/(# support classes). Number of major iterations (around spiral model). Number of completed contracts. 14
- 15. 15