What is the purpose and advantages of using polymorphism in object-oriented programming?

Polymorphism is a principle of object-oriented programming that allows objects of different classes to have the same interface but different implementations of methods.

Advantages of polymorphism:

• Flexibility and extensibility of code: you can write general code that works with the base type, and specific behavior is determined in subclasses.
• Simplification of maintenance and modification: adding new types does not require changing existing code.
• Improved readability and reusability: a common interface makes it easier to understand and use classes.

Example in Swift:

class Animal {
    func sound() {
        print("Some sound")
    }
}

class Dog: Animal {
    override func sound() {
        print("Bark")
    }
}

class Cat: Animal {
    override func sound() {
        print("Meow")
    }
}

let animals: [Animal] = [Dog(), Cat()]
for animal in animals {
    animal.sound()  // Calls the appropriate method in each subclass
}