arrays - 如何将结构加载到数组中？

Question

我正在尝试加载一个包含结构数据的简单数组。
我读过不使用元组所以我使用结构。

以下是在 Playground 上写的；但数组仍然为零。

我做错了什么？

struct person {
    var firstName:String?
    var lastName:String?
    init(firstName:String, lastName:String) {
        self.firstName = firstName
        self.lastName = lastName
    }
}

let john = person(firstName: "John", lastName: "Doe")
let rich = person(firstName: "Richard", lastName: "Brauer")
let ric = person(firstName: "Ric", lastName: "Lee")
let Merrideth = person(firstName: "Merrideth", lastName: "Lind")

var myPeople:[person]?

myPeople?.append(john)
myPeople?.append(rich)
myPeople?.append(ric)
myPeople?.append(Merrideth)

println(myPeople)

Answer 1

var myPeople:[person]? 只是一个声明，所以之后数组仍然是 nil。在 myPeople?.append(john) 中使用了可选链接，并且仅当 myPeople 不为 nil 时才执行 append。尝试

var myPeople:[person]? = [] 
myPeople?.append(john)

或

var myPeople:[person] = [] 
myPeople.append(john)