c++???
我以前听说先学Ｃ语言才能学c++，所以我一直没学c++，Ｃ++的最大做用是什么呀？ 问题点数：0、回复次数：10Top
1 楼jp1984（mathfrog）回复于 2004-04-03 00:34:12 得分 0
没有最大的作用。 。C和C+都是做底层工作的。。 比如嵌入式开发什么的。。 C++向下兼容C，所以你完全可以直接跳过C而直接学C++， 可以说这两者没有直接的联系。。不过有C的基础可能会更好理解C++中的概念。。Top
2 楼angelo23（angelo）回复于 2004-04-03 00:41:34 得分 0
1.5 Use of C++
C++ is used by hundreds of thousands of programmers in essentially every application domain.
This use is supported by about a dozen independent implementations, hundreds of libraries, hundreds
of textbooks, several technical journals, many conferences, and innumerable consultants.
Training and education at a variety of levels are widely available.
Early applications tended to have a strong systems programming flavor. For example, several
major operating systems have been written in C++ [Campbell,1987] [Rozier,1988] [Hamilton,1993]
[Berg,1995] [Parrington,1995] and many more have key parts done in C++. I considered uncompromising
low-level efficiency essential for C++. This allows us to use C++ to write device drivers
and other software that rely on direct manipulation of hardware under real-time constraints. In such
code, predictability of performance is at least as important as raw speed. Often, so is compactness
of the resulting system. C++ was designed so that every language feature is usable in code under
severe time and space constraints [Stroustrup,1994,§4.5].
Most applications have sections of code that are critical for acceptable performance. However,
the largest amount of code is not in such sections. For most code, maintainability, ease of extension,
and ease of testing is key. C++’s support for these concerns has led to its widespread use
where reliability is a must and in areas where requirements change significantly over time. Examples
are banking, trading, insurance, telecommunications, and military applications. For years, the
central control of the U.S. long-distance telephone system has relied on C++ and every 800 call
(that is, a call paid for by the called party) has been routed by a C++ program [Kamath,1993].
Many such applications are large and long-lived. As a result, stability, compatibility, and scalability
have been constant concerns in the development of C++. Million-line C++ programs are not
uncommon.
Like C, C++ wasn’t specifically designed with numerical computation in mind. However, much
numerical, scientific, and engineering computation is done in C++. A major reason for this is that
traditional numerical work must often be combined with graphics and with computations relying on
data structures that don’t fit into the traditional Fortran mold [Budge,1992] [Barton,1994]. Graphics
and user interfaces are areas in which C++ is heavily used. Anyone who has used either an
Apple Macintosh or a PC running Windows has indirectly used C++ because the primary user interfaces
of these systems are C++ programs. In addition, some of the most popular libraries supporting
X for UNIX are written in C++. Thus, C++ is a common choice for the vast number of applications
in which the user interface is a major part.
All of this points to what may be C++’s greatest strength: its ability to be used effectively for
applications that require work in a variety of application areas. It is quite common to find an application
that involves local and wide-area networking, numerics, graphics, user interaction, and database
access. Traditionally, such application areas have been considered distinct, and they have
most often been served by distinct technical communities using a variety of programming languages.
However, C++ has been widely used in all of those areas. Furthermore, it is able to coexist
with code fragments and programs written in other languages.
C++ is widely used for teaching and research. This has surprised some who – correctly – point
out that C++ isn’t the smallest or cleanest language ever designed. It is, however
– clean enough for successful teaching of basic concepts,
– realistic, efficient, and flexible enough for demanding projects,
– available enough for organizations and collaborations relying on diverse development and
execution environments,
– comprehensive enough to be a vehicle for teaching advanced concepts and techniques, and
– commercial enough to be a vehicle for putting what is learned into non-academic use.
C++ is a language that you can grow with.Top
3 楼theoldman（跛脚老人）回复于 2004-04-03 00:41:39 得分 0
C++与C的最大区别是在其思想差异，如果是做工程的话C++会比C好用。尽管两者有着不少的差别，但完全可以直接学习C++，当然能有C底子则更易上手，不过在《C++编程思想》中作者建议就算懂了C，学习C++时还是把它当成新语言来学，个人认为其说得还是有道理的。Top
4 楼angelo23（angelo）回复于 2004-04-03 00:42:12 得分 0
1.2 Learning C++
The most important thing to do when learning C++ is to focus on concepts and not get lost in
language-technical details. The purpose of learning a programming language is to become a better
programmer; that is, to become more effective at designing and implementing new systems and at
maintaining old ones. For this, an appreciation of programming and design techniques is far more
important than an understanding of details; that understanding comes with time and practice.
C++ supports a variety of programming styles. All are based on strong static type checking, and
most aim at achieving a high level of abstraction and a direct representation of the programmer’s
ideas. Each style can achieve its aims effectively while maintaining run-time and space efficiency.
A programmer coming from a different language (say C, Fortran, Smalltalk, Lisp, ML, Ada, Eiffel,
Pascal, or Modula-2) should realize that to gain the benefits of C++, they must spend time learning
and internalizing programming styles and techniques suitable to C++. The same applies to programmers
used to an earlier and less expressive version of C++.
Thoughtlessly applying techniques effective in one language to another typically leads to awkward,
poorly performing, and hard-to-maintain code. Such code is also most frustrating to write
because every line of code and every compiler error message reminds the programmer that the language
used differs from ‘‘the old language.’’ You can write in the style of Fortran, C, Smalltalk,
etc., in any language, but doing so is neither pleasant nor economical in a language with a different
philosophy. Every language can be a fertile source of ideas of how to write C++ programs.
However, ideas must be transformed into something that fits with the general structure and type
system of C++ in order to be effective in the different context. Over the basic type system of a language,
only Pyrrhic victories are possible.
C++ supports a gradual approach to learning. How you approach learning a new programming
language depends on what you already know and what you aim to learn. There is no one approach
that suits everyone. My assumption is that you are learning C++ to become a better programmer
and designer. That is, I assume that your purpose in learning C++ is not simply to learn a new syntax
for doing things the way you used to, but to learn new and better ways of building systems.
This has to be done gradually because acquiring any significant new skill takes time and requires
practice. Consider how long it would take to learn a new natural language well or to learn to play a
new musical instrument well. Becoming a better system designer is easier and faster, but not as
much easier and faster as most people would like it to be.
It follows that you will be using C++ – often for building real systems – before understanding
every language feature and technique. By supporting several programming paradigms (Chapter 2),
C++ supports productive programming at several levels of expertise. Each new style of programming
adds another tool to your toolbox, but each is effective on its own and each adds to your
effectiveness as a programmer. C++ is organized so that you can learn its concepts in a roughly linear
order and gain practical benefits along the way. This is important because it allows you to gain
benefits roughly in proportion to the effort expended.
In the continuing debate on whether one needs to learn C before C++, I am firmly convinced
that it is best to go directly to C++. C++ is safer, more expressive, and reduces the need to focus on
low-level techniques. It is easier for you to learn the trickier parts of C that are needed to compensate
for its lack of higher-level facilities after you have been exposed to the common subset of C
and C++ and to some of the higher-level techniques supported directly in C++. Appendix B is a
guide for programmers going from C++ to C, say, to deal with legacy code.
Several independently developed and distributed implementations of C++ exist. A wealth of
tools, libraries, and software development environments are also available. A mass of textbooks,
manuals, journals, newsletters, electronic bulletin boards, mailing lists, conferences, and courses
are available to inform you about the latest developments in C++, its use, tools, libraries, implementations,
etc. If you plan to use C++ seriously, I strongly suggest that you gain access to such
sources. Each has its own emphasis and bias, so use at least two. For example, see [Barton,1994],
[Booch,1994], [Henricson,1997], [Koenig,1997], [Martin,1995].Top
5 楼angelo23（angelo）回复于 2004-04-03 00:43:14 得分 0
TC++PL上原文照抄～楼主不妨一看（绝对值得一看，就当练练英语也好:-) ）Top
6 楼hwbin2008（影子）回复于 2004-04-03 02:00:51 得分 0
拿超级解霸读出来,也别有一番味道Top
7 楼angelo23（angelo）回复于 2004-04-03 08:16:31 得分 0
超级解霸有翻译功能？Top
8 楼segno（）回复于 2004-04-03 08:35:07 得分 0
超级解霸可以朗读。Top
9 楼tomren（小泥人）回复于 2004-04-03 08:38:00 得分 0
I 服了 YOU !Top
10 楼hqlsy（强）回复于 2004-04-03 11:12:56 得分 0
C++向下兼容C，你完全可以直接跳过C而直接学C++。
Top
