C Language
Before we start any complex program in C, we must understand what really C is, how it came into existence and how it differs from other languages of that time. In this tutorial I will try to talk about these issues and then move towards view structure of a typical C program.
C is a programming language which born at “AT & T’s Bell Laboratories” of USA in 1972. It was written by Dennis Ritchie. This language was created for a specific purpose: to design the UNIX operating system (which is used on many computers). From the beginning, C was intended to be useful--to allow busy programmers to get things done.
Because C is such a powerful, dominant and supple language, its use quickly spread beyond Bell Labs. In the late 70’s C began to replace widespread well-known languages of that time like PL/I, ALGOL etc. Programmers everywhere began using it to write all sorts of programs. Soon, however, different organizations began applying their own versions of C with a subtle difference. This posed a serious problem for system developers. To solve this problem, the American National Standards Institute (ANSI) formed a committee in 1983 to establish a standard definition of C. This committee approved a version of C in 1989 which is known as ANSI C. With few exceptions, every modern C compiler has the ability to adhere to this standard. ANSI C was then approved by the International Standards Organization (ISO) in 1990.
Now, what about the name? Why it was named C, why not something else. The C language is so named because its predecessor was called B. The B language was developed by Ken Thompson of Bell Labs.
Why Use C?
In today's world of computer programming, there are many high-level languages to choose from, such as Pascal, BASIC, and Java. But C stands apart from all these languages. This is due to its many desirable qualities. It is a robust language whose rich set of built-in functions and operators can be used to write any complex logic program. The C language compiler combines the capabilities of a low level language with the features of a high level language. Therefore the language is suitable for writing both system software as well as business packages & other software. You will many compilers available in the market written in C.
• Program written in c are very efficient and fast. This is due to its variety of data types and powerful operators. It is many time faster than BASIC. This helps developers in saving their valuable time.
• C is a powerful and flexible language which helps system developers to deliver various complex tasks with ease. C is used for diverse projects as operating systems, word processors, graphics, spreadsheets, and even compilers for other languages.
• C is popular among professional programmers for programming, as a result, a wide variety of C compilers and helpful accessories are available.
• C is highly portable language. This means that a C program written for one computer system (an IBM PC, for example) can be run on another system (a DEC VAX system, perhaps) with little or no modification. Portability is enhanced by the ANSI standard for C, the set of rules for C compilers.
• C’s another striking feature is its ability to extend itself. A C program is basically a collection of various function supported by C library (also known as header files). We can also add our own functions to the C library. These functions can be reused in other applications or programs by passing pieces of information to the functions, you can create useful, reusable code.
• Writing C program with user-defined functions makes program more simple and easy to understand. Breaking a problem in terms of functions makes program debugging, maintenance and testing easier.
As these features shows that C is an excellent choice for your first programming language. But what is C++? You might have heard this term C++ and the programming technique called Object-Oriented Programming (OOP). Possibly you're wondering what the differences are between C and C++ and whether you should learn C or C++.
C++ is a superset of C, means that C++ is the new improved version of C for the latest programming needs. It contains everything C does, plus new additions for OOP concept. If you will learn C++ later, you will find that almost everything which you learnt in C is applicable in C++ too. In learning C, you are not only learning one of today's most powerful and popular programming languages, but you are also preparing yourself for other similar programming languages.
Another language that has gotten lots of attention is Java for its OOP and portability. Java, just like C++, is based on C. If later you decide to learn Java, you will find that almost everything you learned about C applies here
C++
C++ (pronounced "see plus plus") is a general-purpose, high-level programming language with low-level facilities. It is a statically typed free-form multi-paradigm language supporting procedural programming, data abstraction, object-oriented programming, generic programming and RTTI. Since the 1990s, C++ has been one of the most popular commercial programming languages.Bjarne Stroustrup developed C++ (originally named "C with Classes") in 1983 at Bell Labs as an enhancement to the C programming language. Enhancements started with the addition of classes, followed by, among other features, virtual functions, operator overloading, multiple inheritance, templates, and exception handling. The C++ programming language standard was ratified in 1998 as ISO/IEC 14882:1998, the current version of which is the 2003 version, ISO/IEC 14882:2003. A new version of the standard (known informally as C++0x) is being developed.
Stroustrup began work on C with Classes in 1979. The idea of creating a new language originated from Stroustrup's experience in programming for his Ph.D. thesis. Stroustrup found that Simula had features that were very helpful for large software development, but the language was too slow for practical use, while BCPL was fast but too low-level and unsuitable for large software development. When Stroustrup started working in Bell Labs, he had the problem of analyzing the UNIX kernel with respect to distributed computing. Remembering his Ph.D. experience, Stroustrup set out to enhance the C language with Simula-like features. C was chosen because it is general-purpose, fast, and portable. Besides C and Simula, some other languages which inspired him were ALGOL 68, Ada, CLU and ML. At first, the class, derived class, strong type checking, inlining, and default argument features were added to C via Cfront. The first commercial release occurred in October 1985.[1]
In 1983, the name of the language was changed from C with Classes to C++. New features were added including virtual functions, function name and operator overloading, references, constants, user-controlled free-store memory control, improved type checking, and a new single-line comment style with two forward slashes (//). In 1985, the first edition of The C++ Programming Language was released, providing an important reference to the language, as there was not yet an official standard. In 1989, Release 2.0 of C++ was released. New features included multiple inheritance, abstract classes, static member functions, const member functions, and protected members. In 1990, The Annotated C++ Reference Manual was published. This work became the basis for the future standard. Late addition of features included templates, exceptions, namespaces, new casts, and a Boolean type.
As the C++ language evolved, a standard library also evolved with it. The first addition to the C++ standard library was the stream I/O library which provided facilities to replace the traditional C functions such as printf and scanf. Later, among the most significant additions to the standard library, was the Standard Template Library.
After years of work, a joint ANSI-ISO committee standardized C++ in 1998 (ISO/IEC 14882:1998). For some years after the official release of the standard in 1998, the committee processed defect reports, and published a corrected version of the C++ standard in 2003. In 2005, a technical report, called the "Library Technical Report 1" (often known as TR1 for short) was released. While not an official part of the standard, it gives a number of extensions to the standard library which are expected to be included in the next version of C++. Support for TR1 is growing in almost all currently maintained C++ compilers.
