【正文】 access to the machine Data can be destroyed through mistakes or malicious intent. The second weakness of many of the PCbased systems is that of performance. If data volumes grow up to a few thousands of records, performance could be a bottleneck. For anization where growth in data volumes is expected, availability of, the same or patible software on large machines should be considered. This is one of the most mon misconceptions about database management systems that are used in personal puters. Thoroughly prehensive and sophisticated business systems can be developed in dBASE, Paradox and other DBMSs. However, they are created by experienced programmers using the DBMS39。其二是C缺乏性能極高的應(yīng)用程序所需 要的關(guān)鍵功能，包括保證在代碼的特定地方運(yùn)行的內(nèi)聯(lián)函數(shù)和析構(gòu)函數(shù)。其一是該語(yǔ)言不適用于編寫(xiě)時(shí)間急迫或性能非常高的代碼，例如一個(gè)要運(yùn)行 1000 或 1050 次的循環(huán)，并在不需要這些循環(huán)時(shí)，立即清理它們所占用的資源。 C語(yǔ)言本身非常類(lèi)似于 Java，但其中有一些改進(jìn)，因?yàn)?Java 并不是為應(yīng)用于 .NET 環(huán)境而設(shè)計(jì)的。 應(yīng)該指出，對(duì)于上述大多數(shù)特性， 和 Managed C++也具備。 ● 改變編譯器選項(xiàng)，可以把程序編譯為可執(zhí)行文件或 .NET 組件庫(kù)，該組件庫(kù)可以用與 ActiveX 控件 (COM 組件 )相同的方式由其他代碼調(diào)用。 ● 可以使用指針和直接內(nèi)存訪問(wèn)，但 C語(yǔ)言可以在沒(méi)有它們的條件下訪問(wèn)內(nèi)存。這可以用于文檔說(shuō)明，對(duì)編譯有一定的影響 (例 如，把方法標(biāo)記為只在調(diào)試時(shí)編譯 )。 ● 自動(dòng)清理動(dòng)態(tài)分配的內(nèi)存。 ● 定義完整、一致的基本類(lèi)型集。其設(shè)計(jì)與現(xiàn)代開(kāi)發(fā)工具的適應(yīng)性要比其他語(yǔ)言更高，它同時(shí)具有 Visual Basic 的易用性、高性能以及 C++的低級(jí)內(nèi)存訪問(wèn)性。對(duì) C代碼的第 一印象是它非常類(lèi)似于 C++或 Java 代碼。這種描述在技術(shù)上是非常準(zhǔn)確的，但沒(méi)有涉及到該語(yǔ)言的真正優(yōu)點(diǎn)。 Microsoft 在正式場(chǎng)合把 C描述為一種簡(jiǎn)單、現(xiàn)代、面向?qū)ο?、?lèi)型非常安全、派生于 C 和 C++的編程語(yǔ)言。Microsoft 給 C++添加了許多 Microsoft 專(zhuān)用的關(guān)鍵字，并把 VB 演變?yōu)?，保留了一些基本的 VB 語(yǔ)法，但在設(shè)計(jì)上完全不同，從實(shí)際應(yīng)用的角度來(lái)看， 是一種新語(yǔ)言。讓一個(gè)C++開(kāi)發(fā)人員說(shuō)說(shuō)字符串有多少個(gè)定義方式就可以說(shuō)明這一點(diǎn)： char*、 LPTSTR、 string、CString (MFC 版本 )、 CString (WTL 版本 )、 wchar_t*和 OLECHAR*等。其二， Microsoft 同時(shí)還試圖把 C++演變?yōu)橐环N用于在 Windows 上執(zhí)行高性能任務(wù)的語(yǔ)言 —— 在語(yǔ)言中避免添加大量 Microsoft 專(zhuān)用的關(guān)鍵字和各種庫(kù)。遺憾的是，這導(dǎo)致了兩個(gè)問(wèn)題。 另一方面， C++在 ANSI C++語(yǔ)言定義中有其自己的根。其缺點(diǎn)是 Visual Basic 從來(lái)沒(méi)有實(shí)現(xiàn)真正意義上的面向?qū)ο?，所以大型?yīng)用程序很難分解和維護(hù)。雖然 VB 和 C++最終已成為非常強(qiáng)大的語(yǔ)言，但這兩種語(yǔ)言也存在問(wèn)題，因?yàn)樗鼈儽Ａ袅嗽?來(lái)的一些內(nèi)容。武漢理工大學(xué) 本科生畢業(yè)設(shè)計(jì)（論文） 英文翻譯 畢業(yè)設(shè)計(jì)題目： 會(huì)務(wù)管理系統(tǒng)的設(shè)計(jì)與實(shí)現(xiàn) 學(xué)院（系）： 信息工程 學(xué)院 專(zhuān)業(yè)班級(jí)： 電信 0601班 學(xué)生姓名： 肖 曼 指導(dǎo)教師： 王 琳 1 1 《 Professional C Third Edition》 Simon Robinson, Christian Nagel, Jay Glynn, Man Skinner, Karli Watson, Bill Evjen. Wiley Publishing, Inc. 2021 英文原文： Where C Fits In In one sense, C can be seen as being the same thing to programming languages as .NET is to the Windows environment. Just as Microsoft has been adding more and more features to Windows and the Windows API over the past decade, Visual Basic and C++ have undergone expansion. Although Visual Basic and C++ have ended up as hugely powerful languages as a result of this, both languages also suffer from problems due to the legacies of how they have evolved. In the case of Visual Basic 6 and earlier, the main strength of the language was the fact that it was simple to understand and didn’t make many programming tasks easy, largely hiding the details of the Windows API and the COM ponent infrastructure from the developer. The downside to this was that Visual Basic was never truly objectoriented, so that large applications quickly bee disanized and hard to maintain. As well as this, because Visual Basic’s syntax was inherited from early versions of BASIC (which, in turn, was designed to be intuitively simple for beginning programmers to understand, rather than to write large mercial applications), it didn’t really lend itself to wellstructured or objectoriented programs. C++, on the other hand, has its roots in the ANSI C++ language definition. It isn’t pletely ANSI pliant for the simple reason that Microsoft first wrote its C++ piler before the ANSI definition had bee official, but it es close. Unfortunately, this has led to two problems. First, ANSI C++ has its roots in a decadeold state of technology, and this shows up in a lack of support for modern concepts (such as Unicode strings and generating XML documentation), and in some archaic syntax structures designed for the pilers of yesteryear (such as the separation of declaration from definition of member functions). Second, Microsoft has been simultaneously trying to evolve C++ into a language that is designed for highperformance tasks on Windows, and in order to achieve that they’ve been forced to add a huge number of Microsoftspecific keywords as well as various libraries to the language. The result is that on Windows, the language has bee a plete mess. Just ask C++ developers how many definitions for a string they can think of: char*, LPTSTR, string, CString (MFC version), CString (WTL version), wchar_t*, OLECHAR*, and so on. Now enter .NET—a pletely new environment that is going to involve new extensions to both languages. Microsoft has gotten around this by adding yet more Microsoftspecific keywords to C++, and by pletely revamping Visual Basic into Visual Basic .NET, a language that retains some of the basic VB syntax but that is so different in design that we can consider it 2 to be, for all practical purposes, a new language. It’s in this context that Microsoft has decided to give developers an alternative—a language designed specifically for .NET, and designed with a clean slate. Visual C .NET is the result. Officially, Microsoft describes C as a “simple, modern, objectoriented, and typesafe programming language derived from C and C++.” Most independent observers would probably change that to “derived from C, C++, and Java.” Such descriptions are technically accurate but do little to convey the beauty or elegance of the language. Syntactically, C is very similar to both C++ and Java, to such an extent that many keywords are the same, and C also shares the same block structure with braces ({}) to mark blocks of code, and semicolons to separate statements. The first impression of a piece of C code is that it looks quite like C++ or Java code. Behind that initial similarity, however, C is a lot easier to learn than C++, and of parable difficulty to Java. Its design is more in tune with modern developer to