Objective-C Interview Questions and Answers

Objective-C is an object-oriented, general-purpose programming language that adds Smalltalk-style messaging to the C programming language. It was the main programming language used by Apple for the OS X and iOS operating systems, and their respective application programming interfaces (APIs) Cocoa and Cocoa Touch prior to the introduction of Swift. Objective-C is a fundamentally 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.

Objective-C supports an open style of dynamic binding, a style that can accommodate a simple architecture for interactive user interfaces. Messages are not necessarily constrained by either the class of the receiver or even the method name, so a software framework can allow for user choices at runtime and permit developers freedom of expression in their design. (Terminology such as dynamic binding, message, class, and receiver are explained in due course in this document.)

The programming language Objective-C was originally developed in the early 1980s. It was selected as the main language used by NeXT for its Next STEP operating system, from which OS X and iOS are derived. Portable Objective-C programs that do not use the Cocoa or Cocoa Touch libraries, or those using parts that may be ported or re implemented for other systems, can also be compiled for any system supported by GNU Compiler Collection (GCC) or Clang.

Scroll to Top