Difference between revisions of "The History of Objective-C"

Cannot find HTML file objc<htmlet> Before learning the intricacies of a new programming language it is often worth taking a little time to learn about the history and legacy of that language. In this chapter of [[Objective-C 2.0 Essentials]] we will provide a brief overview of the origins of Objective-C and the business history that ultimately led to it becoming the programming language of choice for both Mac OS X and the iPhone. == The C Programming Language == <google>IOSBOX<google> Objective-C is based on a programming language called, quite simply, ''C''. The origins of the C programming language can be traced back nearly 40 years to two engineers named Dennis Ritchie and Ken Thompson working at what is now known as AT&T Bell Labs. At the time, the two were working on developing the UNIX operating system on PDP-7 and PDP-11 systems. After attempts to write this operating system using assembly language (essentially using sequences of instruction codes understood by the processor), it was decided that a higher level, more programmer friendly programming language was required to handle the complexity of an operating system such as UNIX. The first attempt was a language called ''B''. The ''B'' language, which was based on a language called ''BCPL'', was found to be lacking. Taking the next initial from the ''BCPL'' name, the ''C'' language was created and subsequently used to write much of the UNIX operating system kernel and infrastructure. As far as we can tell, ''C'' was so successful that new languages named ''P'' and ''L'' never needed to be created. == The Smalltalk programming Language == The C programming language is what is known as a ''procedural'' language. As such, this means that it lacks features such as object oriented programming. Object oriented programming advocates the creation of small, clearly defined code objects that can be assembled and reused to create more complex systems. An early attempt at an object-oriented programming language was developed by a team including Alan Kay (who later went to work for Apple) and Dan Ingalls at Xerox PARC (Palo Alto Research Center) in the 1970s. This language is known as Smalltalk. == C meets Smalltalk == An interesting history lesson so far, but what does this have to with Objective-C? Well, in the 1980s, two developers named Brad Cox and Tom Love extended the C programming language to support the object oriented features of Smalltalk. This melding of languages ultimately culminated in the creation of Objective-C. Objective-C was subsequently adopted by the Free Software Foundation and released under the terms of the GNU Public License (GPL). == Objective-C and Apple == <htmlet>adsdaqbox_flow.html