openai/gpt-5.6-terra 📝❓🖼️🔢 → 📝

C and Objective-C are related programming languages, but Objective-C adds object-oriented features on top of C.

C

C is a procedural, low-level-to-mid-level language used for systems programming, embedded software, operating systems, and performance-critical code.

Example:

#include <stdio.h>

int main() {
    printf("Hello, world!
");
    return 0;
}

Key characteristics:

• Functions, structs, pointers, arrays
• Manual memory management (malloc, free)
• No built-in classes or objects
• Common for kernels, drivers, embedded systems, and libraries

Objective-C

Objective-C is essentially C plus object-oriented programming features, originally built around the Smalltalk messaging model. It was heavily used for Apple software development before Swift.

Example:

#import <Foundation/Foundation.h>

@interface Greeter : NSObject
- (void)sayHello;
@end

@implementation Greeter
- (void)sayHello {
    NSLog(@"Hello, world!");
}
@end

int main() {
    Greeter *greeter = [[Greeter alloc] init];
    [greeter sayHello];
    return 0;
}

Key characteristics:

• Includes nearly all of C
• Adds classes, objects, inheritance, protocols, and dynamic method dispatch
• Uses bracket syntax for method calls: [object method]
• Commonly uses Apple frameworks such as Foundation and UIKit
• Supports automatic memory management through ARC (Automatic Reference Counting)

Main differences

Important relationship

Objective-C is a superset of C in practice: you can write ordinary C code inside an Objective-C program. For example, Objective-C files often contain C functions, structs, and pointer operations.

Today, Apple development generally favors Swift, but Objective-C remains common in older codebases, frameworks, and interoperability scenarios.