¶ Objective C
¶ Programming Languages
Introduction to the World of Objective-C
There’s something uniquely charming about stepping into a programming language with history in its bones. Objective-C isn’t one of those shiny new languages that appeared overnight with bold claims and loud marketing. It’s a language that grew, lived, and evolved through decades of real use, carrying the fingerprints of the engineers who shaped the modern Apple ecosystem long before Swift ever existed. If you’re curious about where macOS and iOS began, or if you want to understand the philosophy that guided Apple’s early software design, then walking into the world of Objective-C is like uncovering the architectural blueprints of a familiar city.
This course, spanning a hundred articles, is a journey through that world. It’s not an archaeological dig through outdated technology, and it’s certainly not a nostalgia tour. Objective-C remains a living, present-day language that runs inside millions of devices and underpins countless parts of Apple’s frameworks. Learning it is not only about understanding the past—it’s about gaining fluency in a language that still quietly powers the foundations of macOS, iOS, iPadOS, watchOS, and tvOS.
Before diving into the technical details that await in the rest of this course, it helps to begin with the spirit of Objective-C—why it exists, what it values, how it shaped Apple’s culture, and why developers who spend time with it often describe the experience as eye-opening. There’s a certain magic to grasping the philosophy of a language that blends the expressiveness of Smalltalk with the efficiency of C. And when you understand that combination, Objective-C transforms from something old and mysterious into something elegant and surprisingly modern in its own way.
¶ A Language with Deep Roots
Unlike many languages born from committees or academic ambitions, Objective-C emerged from a desire for practical problem-solving. In the early days, developers were searching for a way to bring the dynamism of Smalltalk—the expressive object-oriented style that encouraged messaging and fluid design—into the world of C, a language famous for its power and speed. Instead of replacing C or hiding it under layers of abstraction, Objective-C wrapped around it, extending it with object-oriented capabilities that felt natural and unobtrusive.
It didn’t try to reinvent programming from scratch. It simply enriched the C environment, offering developers a way to write flexible, message-driven code while still having unfettered access to low-level capabilities. That fusion is part of the reason Objective-C survived for so long, and why many developers who first learned it continue to speak fondly about its design.
When NeXT adopted the language, it became the soul of the NeXTSTEP system—the direct predecessor to macOS. When Apple later acquired NeXT, they didn’t just buy a company; they adopted its philosophy, tools, and culture. Objective-C was part of that inheritance. It went on to power the early years of OS X and eventually iOS, providing the backbone for frameworks like Cocoa and Cocoa Touch.
Understanding Objective-C is, in many ways, understanding the early DNA of Apple’s software ecosystem.
¶ The Character of the Language
At first encounter, Objective-C might seem unusual. Its bracketed message syntax doesn’t look like the curly-brace languages most programmers are used to. Method names read like full sentences. Runtime features behave almost like a living organism. But once you spend a little time with it, the language reveals itself as something surprisingly elegant.
Objective-C code tends to be descriptive and readable. Rather than terse, cryptic function names or compressed syntax, you get expressive, intention-revealing method signatures. That habit of writing code that reads almost like prose has influenced generations of Apple developers, and echoes of that design philosophy can still be felt in Swift today.
Objective-C’s runtime gives it a dynamic nature that feels rare among languages descended from C. Objects can receive messages even if the compiler doesn’t know exactly what those objects will be at compile time. Methods can be added, swapped, or extended. Categories allow you to enhance existing classes, a feature so flexible that developers sometimes have to remind themselves to wield it carefully. Protocols let you define behaviors without enforcing inheritance. And the message-passing system means that the language almost behaves like it’s whispering to objects rather than commanding them.
This blend of dynamism and performance is what makes Objective-C fascinating. You can work close to the metal when you need to, and rise above it with expressive abstractions when you prefer.
¶ The Role of Objective-C Today
It’s impossible to talk about Objective-C without acknowledging Swift, the language Apple introduced with much fanfare as the future of development across its platforms. Swift is powerful and modern, and it’s easy to see why new developers gravitate toward it.
But Swift didn’t replace Objective-C so much as sit alongside it.
Thousands of active apps, frameworks, libraries, and internal systems still use Objective-C. Apple continues to update the language and maintain its ecosystem. And beneath every Swift app lies a bridge into the Objective-C runtime, because Swift interoperates with it so deeply that the two languages often feel like collaborators rather than rivals.
For anyone serious about developing software for the Apple ecosystem—or simply wanting to understand how things work under the hood—Objective-C remains an essential language to know.
Learning it gives you direct access to decades of engineering wisdom. It helps you understand why Apple’s frameworks are designed the way they are, why APIs behave in certain patterns, and why concepts like delegates, notifications, selectors, and key-value coding feel so natural in the Apple world.
Without that context, Swift can often feel like a beautiful library built on top of a foundation you can’t see. With Objective-C, that foundation becomes clear.
¶ The Mindset Behind Objective-C
One of the most interesting parts of learning Objective-C is discovering the mindset it encourages. Unlike some languages that demand strict rules or rigid type systems, Objective-C asks you to think in terms of behavior, messaging, and collaboration.
Instead of forcing you to create long inheritance chains, it nudges you toward composition. Instead of locking you into early binding, it allows flexibility through late binding. Instead of treating code as something static and predetermined, it opens the door to runtime introspection and modification.
These features make the language feel alive. It adapts, responds, and exposes its internal workings in ways that many modern languages hide behind layers of abstraction. For someone who values transparency and control, this is invigorating.
It also fosters a certain craftsmanship. Because the language doesn’t try to protect you from every possible mistake, you learn to write thoughtful code. Memory management, even with ARC, teaches you responsibility. Runtime messaging teaches you intentional design. Understanding the role of selectors, categories, and method swizzling gives you respect for the runtime’s power.
There’s a clarity in this approach that many developers come to appreciate deeply.
¶ Why Learn Objective-C Now?
Some might wonder why, in a world increasingly dominated by Swift, Python, JavaScript, and newer languages, anyone should spend time learning Objective-C. The answer is surprisingly simple: because it gives you an understanding of Apple’s platforms that no other language can.
If you want to write apps that interact with older codebases, Objective-C is essential. If you want to understand how Cocoa and Cocoa Touch operate at their core, Objective-C is the key. If you plan on maintaining, extending, or debugging legacy code—or even building tools that interface with Apple frameworks—Objective-C is irreplaceable.
More than that, learning a language with such a deep heritage enriches your perspective as a programmer. It teaches lessons about design, architecture, and flexibility that transfer beautifully into any other language you may use.
Objective-C is not a relic. It is a durable, battle-tested tool that continues to serve developers today.
¶ What Awaits You in This Course
The goal of this course is to walk you through Objective-C in a way that feels natural, human, and engaging. Over the next ninety-nine articles, you’ll encounter everything from basic syntax to advanced runtime behavior, from memory management to interoperating with Swift, from Foundation classes to patterns that have shaped the Apple ecosystem for years.
But before you begin that deeper exploration, it’s worth grounding yourself in the spirit of the language. Objective-C isn’t just a technical framework—it’s part of the story of modern software development, part of the evolution of Apple’s platforms, and part of the broader conversation about how languages adapt to the needs of developers.
Once you understand its personality, everything else falls into place more easily.
¶ Entering the Journey
As you start this course, imagine yourself stepping into a workshop filled with the tools and materials that built the world of Apple software. Objective-C is one of those tools—time-tested, reliable, flexible, and designed with a specific philosophy that continues to influence modern languages.
You’re not learning a museum piece. You’re learning a language that has shaped the design of frameworks used by millions of developers, supported products used by billions of people, and introduced ideas that continue to echo across the industry.
This course will guide you through that world with care, depth, and curiosity.
Whether you're approaching Objective-C with nostalgic interest, professional necessity, or pure curiosity, you’re stepping into a language that offers far more than most people realize.
And now, the journey begins.
¶ Objective-C
¶ Beginner Level
1. Introduction to Objective-C: A Modern, Object-Oriented Programming Language
2. Setting Up Your Objective-C Development Environment
3. Your First Objective-C Program: Writing "Hello, World!"
4. Understanding Objective-C Syntax and Structure
5. Variables, Constants, and Data Types in Objective-C
6. Basic Data Types in Objective-C: Integer, Float, Boolean, and Char
7. Working with Strings in Objective-C
8. Control Flow in Objective-C: If-Else, Switch, and Loops
9. Functions and Methods in Objective-C: Defining and Calling
10. Understanding Object-Oriented Programming (OOP) Basics
11. Introduction to Classes and Objects in Objective-C
12. Instantiating Objects and Using Instance Variables
13. Using Properties and Instance Variables in Objective-C
14. Basic Memory Management in Objective-C
15. Understanding the @interface and @implementation Directives
16. Understanding Objective-C’s @property and @synthesize
17. Working with Arrays in Objective-C
18. Introduction to Object-Oriented Concepts in Objective-C
19. Introduction to Message Passing in Objective-C
20. Basic Input and Output in Objective-C
¶ Intermediate Level
21. Methods in Depth: Instance vs Class Methods
22. Working with Collections: NSArray, NSDictionary, and NSMutableArray
23. Memory Management with retain, release, and autorelease
24. Introduction to Protocols in Objective-C
25. Using Delegates in Objective-C
26. Object-Oriented Programming: Inheritance and Subclassing
27. Polymorphism and Dynamic Dispatch in Objective-C
28. Using Categories and Extensions in Objective-C
29. Understanding the nil and NULL values in Objective-C
30. Working with Blocks in Objective-C
31. File I/O in Objective-C: Reading and Writing Files
32. Using the Foundation Framework: Strings, Dates, and URLs
33. Error Handling in Objective-C: Try-Catch and NSError
34. Understanding Key-Value Coding (KVC)
35. Understanding Key-Value Observing (KVO)
36. Memory Management Best Practices in Objective-C
37. Creating Custom NSObject Subclasses
38. Working with the Runloop in Objective-C
39. Using Foundation Classes for Network Communication
40. Working with JSON in Objective-C: Serialization and Parsing
41. Understanding Objective-C's Dynamic Nature
42. Using Auto Layout in Objective-C for UI Design
43. Concurrency in Objective-C: GCD (Grand Central Dispatch)
44. Multithreading in Objective-C with NSThread
45. Working with Timers and Delayed Actions in Objective-C
46. Implementing Singleton Design Pattern in Objective-C
47. Working with Notifications and Notification Center
48. Debugging Objective-C Code with Xcode's Debugger
49. Unit Testing in Objective-C: XCTest Framework
50. Developing Command-Line Applications in Objective-C
¶ Advanced Level
51. Advanced Memory Management: ARC (Automatic Reference Counting)
52. Design Patterns in Objective-C: Factory, Singleton, and MVC
53. Creating and Using Custom Frameworks in Objective-C
54. Interfacing with C and C++ Code in Objective-C
55. Dynamic Runtime in Objective-C: Method Swizzling and Messaging
56. Creating Custom Objective-C Runtime Classes
57. Working with Core Data in Objective-C: Model-View-Controller (MVC)
58. Data Persistence with Core Data in Objective-C
59. Core Animation for Advanced UI Design
60. Networking in Objective-C: NSURLSession and Web APIs
61. Advanced Networking: WebSocket and Push Notifications
62. Advanced Error Handling and Recovery in Objective-C
63. Optimizing Memory Usage and Performance in Objective-C
64. Using Reflection and Introspection in Objective-C
65. Threading and Concurrency with NSOperationQueue
66. Creating and Managing Custom Queues in Objective-C
67. Secure Coding Practices in Objective-C
68. Advanced File Handling in Objective-C: File Manager and File Operations
69. Creating and Using Custom Views and Controls in Objective-C
70. Using Core Graphics for Custom Drawing and Animation
71. Implementing Asynchronous Operations in Objective-C
72. Designing Efficient Algorithms in Objective-C
73. Creating High-Performance Applications in Objective-C
74. Memory Profiling and Leak Detection in Objective-C
75. Using Instruments to Profile and Optimize Objective-C Code
76. Advanced Unit Testing and Test-Driven Development (TDD) in Objective-C
77. Building and Distributing Objective-C Frameworks
78. Integrating Objective-C with Swift Code
79. Working with Xcode and Swift Playgrounds
80. Cross-Platform Development with Objective-C
81. Building Mac Applications with Objective-C
82. Working with Apple's Cocoa Framework in Objective-C
83. UI Automation with UITesting Framework in Objective-C
84. Creating and Managing Multiple App Targets in Objective-C
85. Handling Memory Warnings and Optimizing Resource Usage
86. Managing App Lifecycle Events in Objective-C
87. Accessing and Using iOS Hardware Features in Objective-C
88. Core Location and Maps in Objective-C
89. Location-Based Services in Objective-C
90. Integrating Third-Party Libraries and Frameworks in Objective-C
91. Building Custom iOS Animations with UIKit
92. Testing Network and API Requests in Objective-C
93. Building App Extensions in Objective-C
94. Creating Advanced Custom UI Elements in Objective-C
95. Implementing Background Tasks and Push Notifications in Objective-C
96. Optimizing for Battery Life in Objective-C Applications
97. Automating Build and Deployment with Xcode and Fastlane
98. Integrating Objective-C with Web Services and Cloud APIs
99. The Future of Objective-C: Maintaining Legacy Code in a Swift World
100. Advanced Objective-C Features: Dynamic Property Wrappers and Associated Objects