c++编程-外文文献.doc

附件一 外文原文 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 programmers 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 hardware 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 of 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 factory 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 different 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 often 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 imparts 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 programming paradigms, help us to think about problems and formulate solutions. Software Design through Paradigms When designing small computer programs or large software systems, we often have a mental model of the problem we are trying t