C vs C++

Difference between c and c++

History of C Language

The C programming language was designed by Dennie's Ritchie in the early 1970s at Bell Laboratories. It was first used system implementation language for the nascent Unix operating system. The main reason to devised C was to overcome the limitations of B. It was Derived from the type-less language BCPL ((Basic Combined Programming Language). C was was the evolution of B and BCPL by incorporating type checking. It was originally intended for use in writing compilers for other languages.

History of C++

C++ was devised by Bjarne Stroustrup in 1983 at Bell Laboratories. It is an extension of C by adding some enhancements to C language. Bjarne combined the simula's(a language designed for making simulations, created by Ole-Johan Dahl and Kristen Nygaard) features of object oriented and the efficiency of C. The new features added to language are templates, namespaces, exception handling and use of standary library.

Difference between c and c++

• C does not have any classes or objects. It is procedure and function driven. There is no concept of access through objects and structures are the only place where there is a access through a compacted variable. c++ is object oriented.

• C structures have a different behavior compared to c++ structures. Structures in c do not accept functions as their parts.

• C input/output is based on library and the processes are carried out by including functions. C++ i/o is made through console commands cin and cout.

• C functions do not support overloading. Operator overloading is a process in which the same function has two or more different behaviors based on the data input by the user.

• C does not support new or delete commands. The memory operations to free or allocate memory in c are carried out by malloc() and free().

• Undeclared functions in c++ are not allowed. The function has to have a prototype defined before the main() before use in c++ although in c the functions can be declared at the point of use.

• After declaring structures and enumerators in c we cannot declare the variable for the structure right after the end of the structure as in c++.

• For an int main() in c++ we may not write a return statement but the return is mandatory in c if we are using int main().

• In C++ identifiers are not allowed to contain two or more consecutive underscores in any position. C identifiers cannot start with two or more consecutive underscores, but may contain them in other positions.

• C has a top down approach whereas c++ has a bottom up approach.

• In c a character constant is automatically elevated to an integer whereas in c++ this is not the case.

• In c declaring the global variable several times is allowed but this is not allowed in c++.

More Detail

• The C programming language was designed by Dennies Ritchie in the early 1970s at Bell Laboratories. It was first used system implementation language for the nascent Unix operating system. The main reason to devised C was to overcome the limitations of B. It was Derived from the type-less language BCPL ((Basic Combined Programming Language). C was was the evolution of B and BCPL by incorporating type checking. It was originally intended for use in writing compilers for other languages.
• C++ was devised by Bjarne Stroustrup in 1983 at Bell Laboratories. It is an extension of C by adding some enhancements to C language. Bjarne combined the simula's(a language designed for making simulations, created by Ole-Johan Dahl and Kristen Nygaard) features of object oriented and the efficiency of C. The new features added to language are templates, namespaces, exception handling and use of standary library.
• C and C++ are no more language for writing compilers and other languages, these general purpose languages are used worldwide in every field.
• C was the C++ predecessor. As it's name implies, a lot of C remains in C++. Although not actually being more powerful than C, C++ allows the programmer to more easily manage and operate with Objects, using an OOP (Object Oriented Programming) concept.
• The main difference between C and C++ is that C++ is object oriented while C is function or procedure oriented. Object oriented programming paradigm is focused on writing programs that are more readable and maintainable. It also helps the reuse of code by packaging a group of similar objects or using the concept of component programming model. It helps thinking in a logical way by using the concept of real world concepts of objects, inheritance and polymorphism. It should be noted that there are also some drawbacks of such features. For example using polymorphism in a program can slow down the performance of that program.
• On the other hand, functional and procedural programming focus primarily on the actions and events, and the programming model focuses on the logical assertions that trigger execution of program code.
• C++ allows the programmer to create classes, which are somewhat similar to C structures. However, to a class can be assigned methods, functions associated to it, of various prototypes, which can access and operate within the class, somewhat like C functions often operate on a supplied handler pointer.
• Although it is possible to implement anything which C++ could implement in C, C++ aids to standarize a way in which objects are created and managed, whereas the C programmer who implements the same system has a lot of liberty on how to actually implement the internals, and style among programmers will vary alot on the design choices made.
• In C, some will prefer the handler-type, where a main function initializes a handler, and that handler can be supplied to other functions of the library as an object to operate on/through. Others will even want to have that handler link all the related function pointers within it which then must be called using a convention closer to C++.
• To finish this discussion, C++ applications are generally slower at runtime, and are much slower to compile than C programs. The low-level infrastructure for C++ binary execution is also larger. For these reasons C is always commonly used even if C++ has a lot of popularity, and will probably continue to be used in projects where size and speed are primary concerns, and portable code still required (assembly would be unsuitable then).
• Another difference is that, type checking for example is much more rigid in C++ than it is in C, so many a program that compiles just fine under a C compiler will result in many warnings and errors under a C++ compiler.
• So, while C++ might be seen as "C with classes" by some, it actually is different and targeted at a different audience. C still is the best choice for code that has to be fast while still being reasonably readable and portable, eg. device drivers. C++ on the other hand is mainly used in large projects of millions of lines of code, where C code would become unmaintainable. This is mainly due to the possibility to reuse existing code by exploiting the OOP concepts of polymorphism and inheritance.