If you’re interested in developing apps for Apple platforms like iOS or macOS, you’ll need to learn Objective-C. While Swift has become Apple’s main programming language in recent years, Objective-C is still used extensively in existing iOS and Mac codebases. Learning Objective-C is a great way to unlock your ability to work on these established codebases or maintain older apps.As I level up my iOS development skills, I’ve been diving deep into Objective-C – the legacy language that still powers much of the Apple ecosystem behind the scenes.While Swift may be the future, Objective-C remains incredibly relevant:
- It has a clean, small set of syntax to learn
- Most existing iOS codebases still use Objective-C
- Direct access to Apple frameworks and hardware capabilities
As an object-oriented language, Objective-C gives the power to elegantly model real-world entities. With features like:
- Encapsulation – Group data and actions into class definitions
- Inheritance – Create subclass hierarchies, inheriting parent characteristics
- Polymorphism – Treat objects consistently despite differing internal logic
It’s been a fun ride getting comfortable with bracket syntax, protocols for abstraction, categories for modular code organization, and other fundamentals.While modern conveniences like method overloading and generics are missing, the extensive Cocoa libraries and performance focused design make Objective-C a battle-tested choice for app development.Understanding this history and jumping into the trenches has level up my perspective. Well worth the investment for any aspiring iOS engineer!
An Introduction to Objective-C
Objective-C is a general-purpose, object-oriented programming language used primarily for developing software on Apple platforms like iOS, macOS, watchOS, and tvOS. Understanding what sets Objective-C apart as a language is key for those looking to build Apple platform apps.
Objective-C Origins
The origins of Objective-C can be traced back to the early 1980s. It was created as an extension of the C programming language to add object-oriented capabilities by taking concepts from Smalltalk. The “Objective” in the name refers to being object-oriented while still keeping C procedural code execution and abilities like direct hardware access.
Key Language Characteristics
As an object-oriented language, Objective-C is focused heavily on defining classes and objects to represent real-world items and leverage abstraction. Important concepts include protocols (establishing method interfaces), categories (extending classes), and frameworks (reusable code libraries).
Objective-C code also has a distinctive syntax with method calls inside brackets and extensive use of defined constants to enable better documentation support. Strong typing means declaring explicit types for variables, arguments, etc to catch more errors during compile time.
Development Environment
The standard IDE for Objective-C development is Xcode from Apple which includes an editor, compiler, debugger and interface design tools. Most Objective-C code also relies heavily on Apple’s Cocoa and Cocoa Touch frameworks which provide stock UI elements and platform capabilities support.
Since Objective-C inherits benefits directly from C, it maintains great performance with the ability to manipulate hardware and memory directly while adding OOP organization. Apps written in Objective-C can co-exist and share code with apps written in Swift as well for ultimate flexibility.
Use Cases
Due to its slow decline over the years, Objective-C is now primarily used for developing apps targeting macOS or older/existing iOS codebases instead of brand new iOS apps. However, despite the rise of Swift, Objective-C retains strong relevance today due to the huge collection of Objective-C libraries and frameworks filling essential needs. Understanding Objective-C continues to be a valuable skill for working on Apple’s platforms.
For those interested in engineering Apple software, learning Objective-C is certainly a worthwhile investment of time and energy for both existing project participation and inheriting a proven language design influencing modern languages like Swift.
Getting Started
The best way to start learning Objective-C is to have a project in mind that will motivate you through the learning process. This could be an iOS or Mac app you’ve been wanting to build or contributing to an open source project written in Objective-C. Having a practical goal will help the language stick.
You should also make sure you have a grasp of core programming concepts like variables, functions, conditional logic and object-oriented principles. While not required, having experience with another programming language can make picking up Objective-C easier.
The key resources you’ll need are an Objective-C compiler and editor. For iOS development, Xcode provides everything you need to start writing Objective-C code. For Mac development, Xcode can still be used or you can explore editor options like Emacs.
Learning Syntax and Concepts
When first getting exposure to Objective-C after experience in other languages, the extensive use of brackets and punctuation can seem foreign. Take time to thoroughly learn the syntax and proper construct formatting.
Objective-C makes heavy use of defined methods and extensive naming conventions, so understanding these will be important when reading/writing code. Likewise, grasp key Objective-C language elements like protocols, categories and frameworks that enable unique capabilities on Apple platforms.
Immersing yourself in quality books and courses instead of fragmented online resources will help you build a solid base of knowledge. Taking things step-by-step when experimenting with writing actual Objective-C code is critical as well to progressing up the learning curve.
Where To Go From Here
Once you have a handle on basic principles, expand your knowledge by building an actual simple app from start to finish or trying out exclusive Objective-C features like blocks and fast enumeration. Making small iterations and continuing projects will help you learn concepts deeply over passively absorbing information.
Confidently coding in Objective-C will open you up to contribute to the vast ecosystem of mature projects in the language as well as build apps leveraging tried and true Objective-C libraries. With some dedicated upfront time investment in learning, you’ll have a highly valued skill to engineering high-quality software on Apple devices.
// AppDelegate.h
#import <UIKit/UIKit.h>
@interface AppDelegate : UIResponder <UIApplicationDelegate>
@property (strong, nonatomic) UIWindow *window;
@end
// AppDelegate.m
#import "AppDelegate.h"
@interface AppDelegate ()
@end
@implementation AppDelegate
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
// Override point for customization after application launch.
return YES;
}
@end
// ViewController.h
#import <UIKit/UIKit.h>
@interface ViewController : UIViewController
@end
// ViewController.m
#import "ViewController.h"
@interface ViewController ()
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(100, 100, 150, 50)];
label.text = @"Hello World!";
[self.view addSubview:label];
}
@endInterfaces in Objective-C
Interfaces play a pivotal role in Objective-C programming. An interface declares methods that a class must implement. It’s similar to abstract classes or interfaces in other languages.
Defining interfaces allows you to set a contract for what methods a class should contain without having to provide the implementation yet. This enables features like abstraction and polymorphism. You can then write separate concrete subclasses later that fulfill the interface requirements.
Some key interface concepts in Objective-C include:
- Protocol – A protocol defines methods and properties that other classes must implement. Any class, structure or enumeration can adopt a protocol.
- Abstract superclass – An abstract parent class can declare required methods that child subclasses override. Subclassing provides inheritance benefits.
- Categories – Allow you to extend existing classes with new methods without subclassing. Keep related functionality together.
As I wrap up this deep dive into Objective-C basics, I’m amazed by the large yet well crafted ecosystem supporting Apple’s platforms. The language design promotes thoughtful organization and planning ahead for extensibility via protocols and categories.
Xcode offers a robust environment to get comfortably ramped up and experiment. While more verbose than Swift, Objective-C forces you to intimately understand every method call and mechanism. And the abundant mature libraries make building advanced apps approachable.
While I’ll continue exploring Swift for new projects, I have a renewed appreciation for Objective-C and how it empowers crafting high quality apps. Apple’s commitment to backwards compatibility gives me confidence time invested mastering this legacy toolbox will continue paying dividends for years. I look forward to building on this foundation as I keep pushing my iOS skills further!