The Differences Between Objective-C and Swift

App development programing languages have evolved substantially throughout the years. What once seemed to be the rarest of skills in programming platforms, mobile programming languages, specifically Apple’s Objective-C and Swift, have come the distance. Today, Swift is easy to pick up, offers better security, adaptability and interoperability. Yet thousands of applications still exist in Objective-C, with many technical teams wondering if there is benefit in upgrading.

In this post, we’ll take a look at the key differences between Objective-C and Swift, and offer code examples of each. We hope this blog post offers considerable value if you are considering upgrading your application to Swift, or are evaluating which language to write your application in.

A Background on Objective-C

Objective-C is a high-level programming language that was first developed in the early 1980s. It was created by Brad Cox and Tom Love at their company, Stepstone. The language was designed as an extension to the C programming language, adding object-oriented programming capabilities to the language.

In 1986, NeXT adopted Objective-C as the primary programming language for their NeXTSTEP operating system. Objective-C then became the primary development language for NeXT's software development kits and frameworks, which were later used to develop the first versions of the macOS and iOS operating systems.

In 1996, Apple acquired NeXT, and with it, the Objective-C language and development frameworks. Objective-C then became the primary language for developing software for the Macintosh, iOS, and macOS. Since then, it has been widely used by millions of developers to build a wide range of applications, from games to productivity tools and everything in between.

 

Along Came Swift

However, in 2014, Apple introduced Swift, a new programming language which was intended to replace Objective-C as the primary language for iOS and macOS development. Swift was designed to be more secure and easier to learn and use than Objective-C. Swift addresses some of the limitations and complexities of Objective-C including improved readability, safety, modernity, performance, and interoperability.

Swift was designed with safety in mind and it introduced several new features such as optionals, automatic reference counting, and type inference. It's a more modern and expressive language than Objective-C and it's designed to work seamlessly with Cocoa Touch and Cocoa frameworks, which are key development frameworks for iOS, iPadOS, macOS, watchOS and tvOS.

Swift evolution, a process of improving the language, has been ongoing since its release, with new versions of Swift being released regularly, introducing new features and improvements to the language. With the release of Swift 5.7.2 in December 2022, the language has continued to evolve and improve, making it more powerful and versatile than ever before.


8 Key Differences Between Objective-C and Swift

While Objective-C and Swift are both used to develop iOS and macOS applications, there are several key differences between the two languages:

  1. Syntax: Swift has a more modern and concise syntax than Objective-C, which can make it easier to read and write code.

  2. Type inference: Swift uses type inference to automatically infer the data types of variables, whereas Objective-C requires variables to be explicitly declared with a data type.

  3. Nullability: Swift has a built-in system for handling null values and optional types, making it less prone to the "nil pointer" crashes that can occur in Objective-C.

  4. Namespaces: Swift has a built-in namespace system, making it easier to organize and organize code.

  5. Interoperability: Swift is designed to be more compatible with other programming languages, such as Python and JavaScript, making it easier to integrate with existing codebases.

  6. Performance: Swift is considered to be faster than Objective-C in terms of performance.

  7. Object-oriented programming: Swift is more focused on object-oriented programming, whereas Objective-C is more focused on procedural programming.

  8. Safety: Swift is designed to be more safe, it has features such as automatic reference counting (ARC) and optionals to prevent common programming errors.

Overall, Swift offers improved performance, safety, and ease of use. Such is the reason why many Objective-C applications are now being re-written in Swift.

Observing Objective-C and Swift Differences in Code

Here is an example of code that declares and initializes a string variable in Objective-C:

NSString *greeting = @"Hello, World!";

And here is the same code written in Swift:

var greeting = "Hello, World!"

As you can see, the syntax is quite different between the two languages, with Swift being more concise and easier to read.


Another example is creating a function in Objective-C:

- (void)printGreeting:(NSString *)greeting {
    NSLog(@"%@", greeting);
}

And the same function in Swift:

func printGreeting(greeting: String)

Again, Swift has a more modern and concise syntax, and it also has a more consistent and expressive way of calling a function.


Here's an example of a class in Objective-C:

@interface Person : NSObject

@property (nonatomic, strong) NSString *name;

- (instancetype)initWithName:(NSString *)name;

- (void)printName;

@end

@implementation Person

- (instancetype)initWithName:(NSString *)name {
    self = [super init];
    if (self) {
        _name = name;
    }
    return self;
}

- (void)printName {
    NSLog(@"%@", _name);
}

@end

And the same class in Swift:

class Person {
    var name: String

    init(name: String) {
        self.name = name
    }

    func printName() 
        
    
}

As you can see, Swift uses a more modern and simplified syntax for creating classes, and it also has a more consistent and expressive way of initializing and calling methods.

Re-Writing Applications in Swift

Even though Swift is the primary language for iOS, tvOS and macOS development, Objective-C is still widely used and supported by Apple, and many existing iOS and macOS apps are still written in Objective-C. However, as of now, Swift is considered one of the fastest-growing programming languages in history. The case for re-writing applications from Objective-C to Swift is apparent for the benefits of added security, ease-of-use, and future-proofing your application.

Shiv Kamal