C

  A high-level programming language developed by Dennis Ritchie called C programming language. The C programming language was devised in the early 1970s as a system implementation language for the nascent UNIX operating system. Derived from the typeless language BCPL, it evolved a type structure; created on a tiny machine as a tool to improve a meager programming environment, it has become one of the dominant languages of today

. Objective-C is defined as set of extensions to the C language. It’s designed to give C full object-oriented programming capabilities, and to do so in a simple and straightforward way. Its additions to C are few and are mostly based on Smalltalk, one of the first object-oriented programming languages.

The Objective-C language was chosen for the Cocoa framework for a variety of reasons. First and foremost, it’s an object-oriented language. The kind of functionality that’s packaged in the Cocoa frameworks can only be delivered through object-oriented techniques.

Second, because Objective-C is an extension of standard ANSI C, existing C programs can be adapted to use the software frameworks without losing any of the work that went into their original development. Moreover, Objective-C is a simple language. Its syntax is small, unambiguous, and easy to learn. Object-oriented programming, with its self-conscious terminology and emphasis on abstract design, often presents a steep learning curve to new recruits. A well-organized language like Objective-C can make becoming a proficient object-oriented programmer that much less difficult.

• Compared to other object oriented languages based on C, Objective-C is very dynamic. The compiler preserves a great deal of information about the objects themselves for use at runtime. Decisions that otherwise might be made at compile time can be postponed until the program is running. This gives Objective-C programs unusual flexibility and power.

C does have a few surprises:

· Many High level languages, like PASCAL, are highly disciplined and structured.

· However beware -- C is much more flexible and free-wheeling. This freedom gives C much more power that experienced users can employ.

Characteristics of C

We briefly list some of C's characteristics that define the language and also have lead to its popularity as a programming language.

· Small size

· Extensive use of function calls

· Loose typing -- unlike PASCAL

· Structured language

· Low level (BitWise) programming readily available

· Pointer implementation - extensive use of pointers for memory, array, structures and functions.

C has now become a widely used professional language for various reasons.

· It has high-level constructs.

· It can handle low-level activities.

· It produces efficient programs.

· It can be compiled on a variety of computers.

References:

http//:dmoz.org/computers/programming/languages/c/tutorials

http//:dmoz.org/computers/programming/languages/c/standards

http//:www.lysator.liu.se/c/history

http//:cm.bell-labs.com/cm/cs/who/dmr/chist.html