Expert: Ralph McArdell - 11/22/2010

Question
Hi,

How can we says that c++ is better than c. What we can do in
c++ which we can not do in c. I know c++ have many extra
features than c. But i need an example situation where c++
need to be used better than c..

Please provide me the information..
Thanks in advance.

Answer
What can we do in C++ that cannot be done in C: pretty much nothing, in the same way that what we can do in C that we cannot do in native machine code or assembler is pretty much nothing. In fact some C++ implementations compile to C.

I cannot give such an example of "need" to use C++ over C. C++ may be chosen to be used over C for a project - or maybe mostly used over C. Even if you "need" to use C++ - e.g. because some other component that has to be used for some reason forces use of a C++ compiler - then you could still write (pretty much) C using the C++ compiler, only dipping into C++ styles (if at all) to use the component in question.

However, C does _not_ have support for most of the abstraction mechanisms that C++ has that allows programs to express type and structure well. C++ also provides stronger type checking than C.

Hence C++ is a better C in that is supports the programming styles of C with better type checking (and notational support) without loss of efficiency, and additionally supports several other programming styles such as object oriented programming and generic programming.

Dr. Bjarne Stroustrup says in "The C++ Programming Language" (3rd / Special edition) that a programming language serves two purposes:

   1/ Being "‘close to the machine’ so that all important aspects of a machine are handled
      simply and efficiently in a way that is reasonably obvious to the programmer. The C
      language was primarily designed with this in mind."

   2/ Being "‘close to the problem to be solved’ so that the concepts of a solution can be
      expressed directly and concisely. The facilities added to C to create C++ were
      primarily designed with this in mind."

Any small program - say around 500 - 2000 lines of code can be made to work by brute force even if it is badly structured and breaks every rule in the good coding style book.

This will not be true of larger systems: 100,000 or multi-million lines of code projects. Without decent structure such programs will have errors introduced as fast as you can take other errors out. Also such large projects would typically be worked on by many people - and often use code in the form of libraries from different vendors - and again C++ facilities such as namespaces are there to help with nasty things such as name clashes between separate libraries.

If you want more specifics on such matters and how C++ came be the way it is then I suggest you read "The Design and Evolution of C++" by Bjarne Stroustrup (http://www2.research.att.com/~bs/dne.html).

For more on this sort of thing checkout a few articles on the Internet, e.g.:

   http://unthought.net/c++/c_vs_c++.html
   http://www2.research.att.com/~bs/bs_faq.html (specifically the C and C++ section)

Hope this helps a little.