Objective-C — Complete Guide

Objectivec Appkit

Objectivec Uikit

What Is Objective-C?

Objective-C is a superset of C that adds object-oriented programming and dynamic messaging for Apple ecosystem development.

Messaging Syntax — Complete Guide

Objective-C uses square bracket messaging [obj message] where the runtime determines which method to call dynamically.

Classes and Objects — Complete Guide

Objective-C separates interface (.h) and implementation (.m) files, using @interface and @implementation directives.

Properties — Complete Guide

Objective-C @property declares attributes with strong/weak, atomic/nonatomic, readwrite/readonly specifiers.

Memory Management — Complete Guide

ARC automatically manages Objective-C memory by inserting retain/release at compile time, replacing MRC.

Foundation Framework — Complete Guide

Foundation provides NSString, NSArray, NSDictionary, NSNumber, and other essential data types.

Categories — Complete Guide

Categories add methods to existing classes without subclassing, including system classes like NSString.

Protocols — Complete Guide

Protocols define method contracts that classes can adopt, implementing delegate patterns throughout iOS.

Blocks — Complete Guide

Blocks are closures capturing local variables, used for callbacks, completion handlers, and enumeration.

Key-Value Observing — Complete Guide

KVO and KVC allow observing property changes and accessing properties by key path dynamically.

Multithreading — Complete Guide

Objective-C multithreading uses NSThread, Grand Central Dispatch (GCD), and NSOperationQueue.

File Handling — Complete Guide

NSFileManager handles file operations: create, read, write, delete, and enumerate directory contents.

Real-World Projects — Complete Guide

Build iOS apps and maintain legacy Objective-C codebases alongside modern Swift integration.