格納プロパティ

class Person {
    var name: String = "Name"
    var age:Int = 0

    func profile() -> String {
        return "I'm \(self.name) and I'm \(self.age) years old."
    }
}


var p = Person()

p.name = "Coddy"
p.age = 10

print("p.name = \(p.name)")
print("p.age = \(p.age)")

class Person {
    var name: String = "Name"
    var age:Int = 10
    private var _lastName:String = ""

   //you coded a getter and setter that returned the private variable _lastName. 
   //You are using _lastName as the local storage here.
    var lastName:String{
    get {
        return _lastName
    }
    set {
        _lastName = newValue
    }
    }

    func profile() -> String {
        return "I'm \(self.name) and I'm \(self.age) years old."
    }

}

var p = Person()

p.name = "Coddy"

print(p.profile())