Inheritance in Objective-C

In Objective-C, inheritance is used to create a new class from an existing class. The new class, referred to as the subclass, inherits properties and methods from the existing class, referred to as the superclass. This allows for code reuse and simplifies the code structure.

To use inheritance in Objective-C, you can declare a subclass with the keyword "subclass" followed by the name of the subclass and the name of the superclass in brackets. For example:

@interface Animal : NSObject
@property NSString* name;
-(void)makeSound;
@end
@interface Cat : Animal

@end

In the above example, the Cat class is a subclass of Animal. This means that the Cat class will inherit the name property and makeSound method from the Animal class.

You can also override methods in the subclass to provide custom functionality. For example:

@implementation Cat
- (void)makeSound {
    NSLog(@"Meow");
}
@end

In the above example, we override the makeSound method inherited from Animal with a custom implementation that outputs "Meow" when called on a Cat object.

Now you can create Cat instances and use both the inherited and overridden properties and methods:

Cat *fluffy = [[Cat alloc] init];
fluffy.name = @"Fluffy";
[fluffy makeSound];

This will output "Meow" in the console.

In conclusion, inheritance is a powerful feature in Objective-C that allows for code reuse and simplifies the code structure. It is achieved by declaring a subclass with the name of the subclass and the name of the superclass in brackets followed by overriding methods to provide custom functionality.