Question

如何快速初始化一个空对象？这就是我所拥有的，但它也想要参数

var userInfo:User = User()

init(email: String, isVerified: String, profileImageURL: String, reputation: String, twitterHandle: String, userName: String) {
        self._email = email
        self._isVerified = isVerified
        self._profileImageURL = profileImageURL
        self._reputation = reputation
        self._twitterHandle = twitterHandle
        self._userName = userName
    }

Answer 1

使用此类可选属性创建类/结构

struct Employee {//struct or class
    var name: String?
    var number: String?
    var position: String?
}

然后，您可以创建一个没有任何值的，具有某些值的对象

let emp = Employee()
let emp = Employee(name: nil, number: nil, position: nil)
let emp = Employee(name: "abc", number: nil, position: "xyz")

通过创建具有默认值参数的init方法，可以在创建对象时忽略

struct Employee {
    var name: String?
    var number: String?
    var position: String?
    init(name: String? = nil, number: String? = nil, position: String? = nil) {
        self.name = name
        self.number = number
        self.position = position
    }
}
let emp = Employee()
let emp = Employee(name: "abc", number: "124", position: "xyz")
let emp = Employee(name: "abc", position: "xyz")
let emp = Employee(number: "124")
let emp = Employee(name: "abc", number: "124")

Answer 2

我假设您正在创建空的User对象，以便以后可以填写信息。我可以看到两个问题：一个，对象属性都必须是变量，而第二个，因为对象很容易犯错并传递错误的信息并不总是对应于真实实体。

更好的方法是定义一组参数，这些参数对于要定义的User对象是必需的，并让所有其他参数为可选参数，或为它们提供默认值。例如，如果我们选择用户名和电子邮件为必填项，并且让个人资料图片为可选，并且isVerified的默认值为false：

class User {
    var userName: String
    var email: String
    var isVerified: Bool
    var profileImageURL: String?

    init(userName: String, email: String, isVerified: Bool = false) {
        self.userName = userName
        self.email = email
        self.isVerified = isVerified
    } 
}

如何快速制作空物体

2 个答案: