面向对象中外文翻译

学院（部）：计算机科学与工程学院专业班级：计算机09-2班

学生姓名：

指导教师：

2013年 5 月 29 日

Object-oriented analysis and design

The basic concept of object-oriented technology and the basic method

1.1 software development method

Computer after birth, computer technology has been developing in high speed condition, the development of computer science and technology by original only depends on the development of hardware to relying more on software development. In fact, the development of software technology has experienced more than generation process.

First generation (50 to 60 s of the 20th century), in programming languages such as FORTRAN and ALGOL technology marked by algorithm

Generation to generation. At that time, the program design on people all creative talents, all rely on tips and tricks. Software productivity is very low, based on the algorithm procedure is very difficult to understand, programmers write their own program over a period of time even after oneself also look not to understand, this to the software modifications, maintenance bring great difficulties. So at the end of the 60 s in the "software crisis".

Second generation (in the late 1970 s to 80 s prevailing), such as PASCAL, and COBOL programming language and relational database management system for a structured system analysis and design techniques. In order to overcome the software crisis, people made efforts to mainly from the following two directions: Methods from the Angle of the management to improve the software development, software engineering method is proposed, and greatly improve the quality and maintainability of the software.

Second is to focus on the analysis in the software development process and design method of research and improvement. Important achievements in this field is developed in the 70 s the rage of structured development method of structured system analysis and design techniques.

Third generation (in the 80 s is still prevalent) represented by Smalltalk, c + + object-oriented software development methods.

Question 1: what is on the development dynamics of object-oriented software development methods?

Traditional structured programming algorithm as the core, the original is closely related to the data and separate to the operation of the data, it is difficult to maintain the consistency of data and operation, its software development method also does not conform to the natural thinking habits, the designed software system solution space and the problem space, the expanded, difficult to understand, modify, and lead to problems in terms of program complexity and software crisis. In order to transcend program complexity barrier, overcome the software crisis, object-oriented software development methods are put forward.

Question 2: what are the advantages of the object-oriented software development method?

Object-oriented development method to change the past traditional on the basis of function analysis and function decomposition of process oriented structural analysis and design method of object-oriented development method to simulate the way people understand and deal with the objective world to analyze the problem, the system as a series of collections of objects, its object-oriented design and analysis of results is mapped to a structure of object-oriented implementation tool, has a more direct correspondence to mapping process, the analysts, designers, and programmers can use the same concept, so that the object oriented software development can simulate more naturally to the activities of the objective world, making the problem space and solution space on the structure as soon as possible. Therefore, adopting the object-oriented method can more effectively developing large software systems. Object-oriented method of encapsulation, inheritance and polymorphism mechanism not only to support software reuse, and the software maintenance, reliable and efficient software system which can realize flexible manufacturing, better to overcome the software crisis. Therefore, it has become a mature method widely used in software development. By the end of the 20th century, object oriented software engineering development gradually mature, especially the formation of the unified modeling language (UML) standard and widely used, the object-oriented software development methods have become the mainstream of the software development technology.

1.2 the basic concept of object-oriented

Object: (1) abstract representations of the objects is an objective entity attributes of the object is described by the data and the data for the operation of the behavior of two parts.

(2)class: class is a collection of objects with the same properties and behavior of abstract description; Internal including attributes and behavior of two main parts.

(3)example: classes is to have the same properties and behavior of a set of abstract descriptions of objects. Therefore, classes can be used as a user-defined type