In object-oriented programming, inheritance refers to one class (known as a sub or child class) being derived from another class (known as a super or parent class). The subclass will inherit methods, properties, and other characteristics from the superclass. With inheritance, we can also create a class hierarchy where we can have multiple layers of inheritance.
Let's look at how we could create a class hierarchy with classes in Swift. We will start off by creating a base class named Animal:
class Animal {
var numberOfLegs = 0
func sleeps() {
print("zzzzz")
}
func walking() {
print("Walking on \(numberOfLegs) legs")
}
func speaking() {
print("No sound")
}
} In the Animal class, we defined one property (numberOfLegs) and three methods (sleeps(), walking(), and speaking()). Now, any class that is a subclass of the Animal class will also have these properties and methods. Let's see how this works by creating two classes...