swift - 从字典中删除可选字符串

Question

我需要将一些参数传递给网络服务，但可选参数也随之而来

if let birthYear = objPet?.birthYear {
        petDict = ["name": (objPet!.name!),
                   "birth_year": birthYear,
                   "gender": 1,
                   "breed": "test"]
    }

petDict控制台

{
    "birth_year" = "Optional(\"2000\")";
    breed = test;
    gender = 1;
    name = 2323;
}

我想要“birth_year”=“2000”。我该怎么做。

类别

class Pet: NSObject {
    var name : String?
    var birthYear : String?
    var birthMonth : String?
    var gender : String?
    var breed : String?
}

Answer 1

你的问题不在于你如何打开 birthYear 。你的问题是 String存储在您的 Pet birthYear 的对象属性(property)字面上是"Optional(2000)" .

您在错误的位置寻找问题的根源。您需要查看创建 Pet 的代码首先是对象。

我执行了以下操作来在 Playground 中重现您的问题:

class Pet: NSObject {
    var name : String?
    var birthYear : String?
    var birthMonth : String?
    var gender : String?
    var breed : String?
}

let objPet: Pet? = Pet()

objPet?.name = "Fido"

let year: Int? = 2000
objPet?.birthYear = "\(year)"   // you have something like this somewhere

if let birthYear = objPet?.birthYear {
    let petDict = ["name": (objPet!.name!),
               "birth_year": birthYear,
               "gender": 1,
               "breed": "test"]
    print(petDict)
}

输出:

{
    "birth_year" = "Optional(2000)";
    breed = test;
    gender = 1;
    name = Fido;
}

如果你改变objPet?.birthYear = "\(year)"至objPet?.birthYear = "\(year!)" ，然后 "Optional"消失了。这表明问题出在 String 上。存储在对象中，而不是您如何解包 String当您创建petDict时.