arrays之如何将结构加载到数组中

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) 

请您参考如下方法:

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)