Object-oriented software development
Object-oriented software development- In the past, the problems faced by software developers were relatively simple, from task analysis to programming, and then to the debugging of the program, it is difficult, the degree is not too big, it can be done by one person or a group. With the rapid increase of software scale, software personnel face the problem is very complicated, and there are many factors that need to be considered. The errors generated and hidden errors may reach to an astonishing degree, this is not something that can be solved in the programming stage. Need to standardize the entire software development process and clarify the software. The tasks of each stage in the development process, while ensuring the correctness of the work of the previous stage, proceed to the next stage work. This is the problem that software engineers needs to study and solve. Object-oriented software development and engineering includes the following parts:
Object oriented analysis (OOA)
The first step of Object-oriented software development is Object Oriented Analysis (OOA). In the system analysis stage of software engineering, system analysts must integrate with users to make precise Accurate analysis and clear description, summarize what the system should do (not how) from a macro perspective. Face right the analysis of the image should be based on object-oriented concepts and methods. In the analysis of the task, from the objective existence of things and the relationship between the related objects (including the attributes and behaviors of the objects) and the relationship between the objects are summarized, and the Objects with the same attributes and behaviors are represented by a class. Establish a need to reflect the real work situation Seek a model. The model formed at this stage is relatively rough (rather than fine).
Object oriented design (OOD)
Second step of Object-oriented software development is Object Oriented Design (OOD), According to the demand model formed in the object-oriented analysis stage, each part is specifically designed. The design of the line class, the design of the class may contain multiple levels (using inheritance and derivation mechanisms). Then these classes are put forward the ideas and methods of program design, including the design of algorithms. In the design stage, no specific plan is involved. Computer language, but a more general description tool (such as pseudo code or flowchart) to describe.
Object oriented programming (OOP)
Third step of Object-oriented software development is Object oriented Programming (OOP), According to the results of object-oriented design, to write it into a program in a computer language, it is obvious that object-oriented Computer language (e.g. C++), Otherwise, the requirements of object-oriented design cannot be achieved.
Object oriented test (OOT)
Fourth step of Object-oriented software development is Object Oriented Test (OOT), After the program is written, the program must be strictly tested before being used by the user. The purpose of the test is to discover Error in the sequence and correct it. Object-oriented testing is to use an object-oriented method to test, using classes as the basis for testing This unit.
Object oriented software maintenance (OOSM)
Fifth step of Object-oriented software development is Object oriented software maintenance (OOSM), Just as any product requires after-sales service and like maintenance, there will be some problems in the use of the software. Or the software vendor wants to improve the performance of the software, which needs to modify the program. Due to the use of object-oriented method development process Sequence makes the maintenance of the program easier. Because of the encapsulation of objects, modifying one object has a great impact on other objects. Using object-oriented methods to maintain the program greatly improves the efficiency of software maintenance.
Among the object-oriented methods, the earliest development was object-oriented programming (OOP), when OOA and OOD were not yet released. Therefore, in order to write object-oriented programs, programmers must also go deep into the field of analysis and design (especially it is the field of design). The OOP at that time actually included the current OOD and OOP stages. For programmers the requirements are relatively high, and many people find it difficult to master. The design of large software is carried out in strict accordance with the five phases of object-oriented software engineering.
The work of the stage is not completed by one person from start to finish, but by different people. In this way, 00P the task of the stage is relatively simple, the programmer only needs to use object-oriented language according to the ideas proposed by OOD Just write the program. In the development of large-scale software, OOP is only a very important part of the object-oriented development process.
If you are dealing with a relatively simple problem, you do not need to strictly follow the above five stages. The planner carries out program design in accordance with an object-oriented method, including class design (or select existing classes) and program design.