Unlocking the Power of Swift Inheritance and Polymorphism

What is Inheritance and Polymorphism in Swift?

Inheritance and polymorphism are two important concepts to understand when developing an app with Swift. Inheritance allows classes to be structured hierarchically so that each class can inherit the characteristics of their parent class (superclass). This helps to reduce code duplication and makes it easier to maintain, thereby increasing code maintainability. Polymorphism basically refers to the ability of objects belonging to different classes to share and use the same methods or functions.

How Does Inheritance Work in Swift?

Inheritance is achieved in Swift by declaring a class as a subclass of its superclass. For example:

class Animal {
  // Code for Animal class
}

class Dog: Animal {
  // Code for Dog class
}

In this example, the Dog class is a subclass of the Animal class, meaning that it inherits the properties and methods from the Animal class. As a result, any instances of the Dog class will have access to the properties and methods declared in the Animal class.

What is Polymorphism in Swift?

Polymorphism allows for objects belonging to different classes to share and use the same methods or functions. For example, consider the following two classes:

class Cat {
  func makeNoise() {
    print("Meow!")
  }
  
  func sleep() {
    print("Zzz...")
  }
}

class Dog {
  func makeNoise() {
    print("Woof!")
  }
  
  func sleep() {
    print("Zzz...")
  }
}

As you can see, both classes have the same method, sleep(). This is an example of polymorphism, since both classes share the same method, even though they belong to different classes.

Overview

Inheritance and polymorphism are two important concepts in Swift programming. Inheritance allows classes to be structured hierarchically, giving each class the ability to inherit the characteristics of their superclass. Polymorphism allows for objects belonging to different classes to share and use the same methods or functions. Understanding how inheritance and polymorphism work is essential for creating maintainable, well-structured code in Swift.