Introduction to Objective-C
Explore the history and key characteristics of Objective-C, understanding its role in the iOS ecosystem and its relationship with C.
Introduction to Objective-C is a free Objective-C iOS Development for Legacy & Enterprise Apps lesson on CoddyKit — lesson 1 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Objective-C iOS Development for Legacy & Enterprise Apps learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
Welcome to Objective-C!
Objective-C shaped the early days of iOS and macOS. Swift is newer, but Objective-C still powers a huge base of existing enterprise apps.
Objective-C's Origins
Born in the early 1980s and adopted by NeXT, Objective-C became Apple's primary language for macOS and iOS after the 1997 acquisition.
Objective-C: C's Super-Set
Objective-C is a superset of C: plain C runs inside it, and it layers object-orientation and message passing on top. Powerful, if tricky at first.
Embrace Object-Orientation
Objective-C is object-oriented, but you do not call methods — you send messages to objects with the bracket syntax [object method:arg].
Dynamic Nature of Objective-C
Objective-C has a powerful dynamic runtime: method dispatch is decided at run time, enabling tricks like swizzling and introspection.
Legacy & Enterprise Importance
Why learn it today? Millions of lines of Objective-C still run shipping apps. You need it to maintain legacy code and migrate to Swift.
Hello, CoddyKit!
Your first program. Note the @autoreleasepool for memory and NSLog, which prints like printf but for Objective-C objects.
#import <Foundation/Foundation.h>
int main(int argc, const char * argv[]) {
@autoreleasepool {
NSLog(@"Hello, CoddyKit!");
}
return 0;
}Understanding the Code
Breaking it down: #import pulls in Foundation, main is the entry point, @autoreleasepool manages memory, and NSLog prints.
Behind the Scenes
Behind the scenes Xcode runs four steps to your program: preprocess, compile, link, and run. It handles all of it for you.
Test Your Knowledge!
Based on what we've learned, consider Objective-C's relationship with the C language.
What We've Learned
Recap: Objective-C is a superset of C with OOP, a dynamic runtime, and deep legacy importance — and you ran your first NSLog program.
Frequently asked questions
Is the “Introduction to Objective-C” lesson free?
Yes — the full text of “Introduction to Objective-C” is free to read here on the web, and the Objective-C iOS Development for Legacy & Enterprise Apps course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Objective-C iOS Development for Legacy & Enterprise Apps course, upgrade to CoddyKit PRO.
What will I learn in “Introduction to Objective-C”?
Explore the history and key characteristics of Objective-C, understanding its role in the iOS ecosystem and its relationship with C. You practise Objective-C iOS Development for Legacy & Enterprise Apps with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start Objective-C iOS Development for Legacy & Enterprise Apps?
No prior experience is required. Objective-C iOS Development for Legacy & Enterprise Apps on CoddyKit is structured for beginners through advanced learners; this is — lesson 1 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “Introduction to Objective-C” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this Objective-C iOS Development for Legacy & Enterprise Apps lesson?
Yes. Every Objective-C iOS Development for Legacy & Enterprise Apps lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- Introduction to Objective-C
- Basic Syntax and Data Types
- Setting Up Xcode for Objective-C
- Working with NSString and Foundation Types