面向?qū)ο蠛蚦語(yǔ)言-外文文獻(xiàn)譯文-object-orientation and c語(yǔ)言編程外文文獻(xiàn)及中文翻譯

1、外文資料譯文1外文資料原文Object-Orientation and C++C++ is just one of many programming languages in use today. Why are there so many languages? Why do new ones appear every few years? Programming languages have evolved to help progr

2、ammers ease the transition from design to implementation. The first programming languages were very dependent on the underlying machine architecture. Writing programs at this level of detail is very cumbersome. Just as h

3、ardware engineers learned how to build computer systems out of other components, language designers also realized that programs could be written at a much higher level, thereby shielding the programmer from the details o

4、f the underlying machine. Why are there such a large number of high-level programming languages? There are languages for accessing large inventory databases, formatting financial reports, controlling robots on the factor

5、y floor, processing lists, controlling satellites in real time, simulating a nuclear reactor, predicting changing atmospheric conditions, playing chess, and drawing circuit boards. Each of these problems requires differe

6、nt sets of data structures and algorithms. Programming languages are tools to help us solve problems. However, there is not one programming language that is best for every type of problem. New programming languages are o

7、ften developed to provide better tools for solving a particular class of problems. Other languages are intended to be useful for a variety of problem domains and are more general purpose. Each programming language impart

8、s a particular programming style or design philosophy on its programmers. With the multitude of programming languages available today, a number of such design philosophies have emerged. These design philosophies, called

9、programming paradigms, help us to think about problems and formulate solutions.1. Software Design through ParadigmsWhen designing small computer programs or large software systems, we often 外文資料譯文3abstraction into progra

10、m design. The purpose of abstraction in programming is to separate behavior from implementation. Procedures are a form of abstraction. The procedure performs some task or function. Other parts of the program call the pro

11、cedure, knowing that it will perform the task correctly and efficiently, but without knowing exactly how the procedure is implemented. THE PROCEDURAL PARADIGM WITH ADTs. DATA ABSTRACTION is concerned with separating the

12、behavior of a data object from its representation or implementation. For example, a stack contains the operations Push, Pop, and IsEmpty. A stack object provides users with these operations, but does not reveal how the s

13、tack is actually implemented. The stack could be implemented using an array or a list. Users of the stack object do not care how the stack is implemented, only that it performs the above operations correctly and efficien

14、tly. Because the underlying implementation of the data object is hidden from its users, the implementation can easily be changed without affecting the programs that use it. When we design algorithms, we often need a part

15、icular data type to use in order to carry out the algorithm's operations. The design of an algorithm is easier if we simply specify the data types of the variables, without worrying about how the actual data type is

16、implemented. We describe the data type by its properties and operations and assume that whatever implementation is chosen, the operations will work correctly and efficiently. Types defined in this way are called ABSTRACT

17、 DATA TYPES (ADTs). The use of abstract data types makes the design of the algorithm more general, and allows us to concentrate on the algorithm at hand without getting bogged down in implementation details. After the al

18、gorithms have been designed, the actual data types will need to be implemented, along with the algorithms. Recently, procedural languages have been extended to support the definition of new data types and provide facilit

19、ies for data abstraction. THE OBJECT-ORIENTED PARADIGM. The object- oriented paradigm retains much of the characteristics of the procedural paradigm, since procedures are still the primary form for composing computations