Swift: Developing iOS Applications

Classes

A class can do everything that a structure can do except that a class can use something called inheritance. A class can inherit the functionality from another class and then extend or customize its behavior. Let's jump right into some code.

Inheriting from another class

Firstly, let's define a class called Building that we can inherit from later:

class Building {
    let squareFootage: Int

    init(squareFootage: Int) {
        self.squareFootage = squareFootage
    }
}
var aBuilding = Building(squareFootage: 1000)

Predictably, a class is defined using the class keyword instead of struct. Otherwise, a class looks extremely similar to a structure. However, we can also see one difference. With a structure, the initializer we created before would not be necessary ...