Inheritance
最后更新于：2022-04-01 02:48:03
## Inheritance
Swift classes do not inherit from a universal base class. Classes you define without specifying a superclass automatically become base classes for you to build upon.
~~~
class Car: Vehicle {
var speed: Double = 0.0
init() {
super.init()
maxPassengers = 5
numberOfWheels = 4
}
override func description() -> String {
return super.description() + "; "
+ "traveling at \(speed) mph"
}
}
~~~
You can present an inherited read-only property as a read-write property by providing both a getter and a setter in your subclass property override. You cannot, however, present an inherited read-write property as a read-only property.
You can prevent a method, property, or subscript from being overridden by marking it as final