Objective-C is a general-purpose, object-oriented programming language that adds Smalltalk-style messaging to the C programming language. It was the main programming language supported by Apple for the macOS, iOS and iPadOS operating systems, and their respective application programming interfaces (APIs) Cocoa and Cocoa Touch until the introduction of Swift in 2014.
The language was originally developed in the early 1980s. It was later selected as the main language used by NeXT for its NeXTSTEP operating system, from which macOS and iOS are derived. Portable Objective-C programs that do not use Apple libraries, or those using parts that may be ported or reimplemented for other systems, can also be compiled for any system supported by GNU Compiler Collection (GCC) or Clang.
Objective-C source code 'implementation' program files usually have .m filename extensions, while Objective-C 'header/interface' files have .h extensions, the same as C header files. Objective-C++ files are denoted with a .mm file extension.
Objective-C was invented in the early 1980s as a means to add Object-Oriented programming capabilities to C. The inventors, Brad Cox and Tom Love, thought that Smalltalk (an early OO language) could provide the tools needed for truly re-usable code and for creating development environments for systems developers.
Cox began by writing a pre-processor for C that allowed for the inclusion of Smalltalk-like code, which would then be rendered into compilable C. This turned into a fully-Object-Oriented C extension.
Objective-C was eventually fully defined and described in the book Object-Oriented Programming: An Evolutionary Approach.
NeXT licensed Objective-C in 1988 and developed several tools based on it. These tools eventually became (after several intermediate steps) the Cocoa development environment, which is used by several Apple systems: Mac OS X, iOS, Apple WatchOS.
For several years now, apps are written for one of these Apple operating systems needed to be written (or compiled to, or run on top of) Objective-C. That situation is changing now as Apple moves its platform to Swift.
In addition to Cocoa, Objective-C is also used in the GNUstep platform, which can run on Linux, Unix, BSD, and Windows environment, and which closely mirrors Cocoa.
F.A.Q about ObjectiveC Development
What is Objective-C?
Objective-C is a general-purpose, object-oriented programming language that adds Smalltalk-style messaging to the C programming language. This is the main programming language used by Apple for the OS X and iOS operating systems and their respective APIs, Cocoa and Cocoa Touch. This reference will take you through a simple and practical approach while learning Objective-C Programming language.
What is OOP?
OOP means Object Oriented Programming; it is a type of programming technique that helps to manage a set of objects in a system. With the help of various programming languages, this method helps to develop several computer programs and applications.
What Objective-C program consists of?
The objective-c program basically consists of:
- Preprocessor commands
- Statements & Expressions