Objective-C Tutorial

Introduction

Objective-C is a superset of C programming language, which makes C object oriented.

  • It was developed by Brad J. Cox at Stepstone Corporation in early 80’s, by adding Smalltalk-80 extensions to C-language.
  • It was originally the main language on NextStep OS which was further adopted by Apple.
  • It is used by Apple as a primary language to develop applications for MAC system and iPhone.

Objective-C, C and Smalltalk

Objective-C is an object oriented programming language that combines features of both, C and Smalltalk.

  • Objective-C extends the procedural C-language with the addition of some new keywords and compiler directives, and uses Smalltalk style for sending messages to objects.
  • The extension of C language into Objective-C is made possible by a runtime library (libobjc) that is generally transparent to the developer.
  • It is possible to compile any C program with Objective-C compiler and therefore, code written in C-language can be freely included in any Objective-C class.
  • Syntaxes of all non-object oriented operations in Objective-C are identical to that of C-language and object oriented operations are the implementation of Smalltalk style messaging.

Features of Objective-C

Being a derivative of C and Smalltalk, Objective-C comprises many features:

  1. It is an object-oriented version of C-language.
  2. It is a powerful language which is easy to learn and sophisticated to work with.
  3. Better understandability of code.
  4. Programmer can use both object oriented and procedural programming strategies as per the requirements.
  5. It provides open dynamic binding via Objective-C runtime library which makes it true object oriented.
  6. It also uses protocols for implementing multiple-inheritance.