Objective-C is a general-purpose, object-oriented programming language that was developed in the early 1980s by Brad Cox and Tom Love. The language was created to extend the capabilities of C, combining its performance and efficiency with the object-oriented programming (OOP) features of Smalltalk. Objective-C added message-passing syntax similar to Smalltalk’s, giving it a dynamic runtime, which made it more flexible than many other compiled languages at the time.
The roots of Objective-C lie in C, so it shares much of its syntax, which made it accessible to existing C programmers. The most significant addition is its syntax for defining and working with objects, which supports the OOP principles of encapsulation, inheritance, and polymorphism. This allowed for the modular structuring of code, which leads to better maintainability and reuse. One of Objective-C’s unique characteristics is its messaging system. Instead of calling methods directly, like in languages such as C++, objects in Objective-C send messages to other objects, which adds a layer of dynamism to method resolution at runtime.
In 1988, NeXT, the company founded by Steve Jobs after leaving Apple, adopted Objective-C as the primary language for its NeXTSTEP operating system, making it the language of choice for app development in the Cocoa framework. When Apple acquired NeXT in 1996, they brought the Cocoa frameworks and Objective-C with them. As a result, Objective-C became the cornerstone of macOS and, later, iOS development. From that point, it became the language most associated with building apps for Apple's ecosystem, powering a vast array of apps and software products on iPhones, iPads, and Macs.
The language has been known for its flexibility due to its dynamic runtime, which gives programmers the ability to change classes and methods at runtime, something that is not easily achievable in more static languages like C++. Objective-C also leverages Automatic Reference Counting (ARC) for memory management, helping developers avoid memory leaks while keeping control of resource management in their programs.
A simple example of Objective-C would look like this:
#import <Foundation/Foundation.h>
@interface Person : NSObject
@property (nonatomic, strong) NSString *name;
- (void)greet;
@end
@implementation Person
- (void)greet {
NSLog(@"Hello, my name is %@", self.name);
}
@end
int main(int argc, const char * argv[]) {
@autoreleasepool {
Person *person = [[Person alloc] init];
person.name = @"Alice";
[person greet];
}
return 0;
}In this example, we define a simple Person class with a name property and a greet method that prints a greeting to the console.
Although Objective-C was the dominant language for Apple software development for many years, it has since been gradually replaced by Swift, a modern programming language introduced by Apple in 2014. Swift was designed to be safer, faster, and easier to read and write compared to Objective-C, though Objective-C is still widely used and remains supported by Apple. Objective-C's legacy endures in the vast amount of existing code written in the language, particularly in the foundational frameworks of Apple's operating systems.
Ultimately, Objective-C remains an important piece of software development history, influencing modern programming paradigms and paving the way for innovations in mobile and desktop app development, especially within the Apple ecosystem. Its dynamic features and its deep integration with Cocoa and Cocoa Touch frameworks made it essential for developers working on macOS and iOS platforms for over two decades.