ios - 一个变量，一个类和两个相同的函数swift

Question

我已经在 google 上搜索这个答案很长时间了，直到我在 stack overflow 创建了一个帐户来问这个问题。

如何编写一个变量来保存一个类，其中包含一些变量，然后调用同一个函数两次？代码中解释:

class Persons {

var oldName = ""
var oldAge = 0
var oldGender = ""
var name = ""
var age = 0
var gender = ""

func create(_ name:String, _ age:Int, _ gender:String) -> String {

    if(age > 100) {
        print("Can't create a person with an age that is over 100!")

        return "Not created!"
    }

    if(gender == "Boy" || gender == "Girl") {

    }
    else {
        print("Gender has to be a girl or a boy!")

        return "Not created!"
    }
    self.name = name
    self.age = age
    self.gender = gender

    self.oldName = name
    self.oldAge = age
    self.oldGender = gender

    print("You just created a \(gender) called: '\(name)' with the age of: '\(age)'!")

    return "Created!"
}

func modify(_ targetName:String, _ newName:String, _ newAge:Int, _ newGender:String) -> String {

    if(age > 100) {
        print("Can't modify a person with an age that is over 100!")
        return "Not modified!"
    }

    if(gender == "Boy" || gender == "Girl") {

    }
    else {
        print("Gender has to be a girl or a boy!")
        return "Not modified!"
    }

    if(targetName != "" && targetName == self.name) {
        self.name = newName
        self.age = newAge
        self.gender = newGender

        print("You just changed \(oldName)'s gender from: \(oldGender) to: \(gender), \(oldName)'s name from: \(oldName) to: \(name) and \(oldName)'s age from: \(oldAge) to: \(age)!")
    }
    else {
        print("Please enter a valid target name or create one!")
    }

    return "Modified!"
}

func delete(_ targetName:String) -> String {

    if(name != "" && targetName == self.name) {
        print("Deleted: \(name)!")
    }
    else {
        print("Please enter a valid target name or create one!")
    }

    return "Deleted!"
}

}

var p = Persons()
p.create("Isak", 11, "Boy")
p.create("Sanne", 7, "Girl") // Here I create another person
p.delete("Isak") // But if I say delete 'Isak' it does not delete him because I created 'Sanne' above!

/*
It would work like this

p.create("Isak", 11, "Boy")
p.delete("Isak")
p.create("Sanne", 7, "Girl")
*/

请帮忙。我花了很长时间才找到答案。如果您需要更多详细信息，请回复，我会尽力解释更多。

Answer 1

这里的问题是您正在使用 Person 的单个实例。当你在做的时候:

p.create("Isak", 11, "Boy")
p.create("Sanne", 7, "Girl") // Here I create another person

尽管您只是在编辑 Person 类的 p 实例的属性，但您并没有创建另一个人。因此，当您删除 Isak 时:

p.delete("Isak")

已经没有 Isak，他被重命名为 Sanne。

要解决这个问题，您应该创建两个独立的 Person 实例:

var p1 = Persons()
var p2 = Persons()
p1.create("Isak", 11, "Boy")
p2.create("Sanne", 7, "Girl") // Here I create another instance of person
p1.delete("Isak")

在此状态下，您有两个人:您刚刚删除的 Sanne 和 Isak，而 Sanne 仍然存在并且可以访问。

如果你想用一个实例来容纳你所有的人，使用这个:

class Person {
var oldName = ""
var oldAge = 0
var oldGender = ""
var name = ""
var age = 0
var gender = ""

func create(_ name:String, _ age:Int, _ gender:String) -> String {

    if(age > 100) {
        print("Can't create a person with an age that is over 100!")

        return "Not created!"
    }

    if(gender == "Boy" || gender == "Girl") {

    }
    else {
        print("Gender has to be a girl or a boy!")

        return "Not created!"
    }
    self.name = name
    self.age = age
    self.gender = gender

    self.oldName = name
    self.oldAge = age
    self.oldGender = gender

    print("You just created a \(gender) called: '\(name)' with the age of: '\(age)'!")

    return "Created!"
}

func modify(_ targetName:String, _ newName:String, _ newAge:Int, _ newGender:String) -> String {

    if(age > 100) {
        print("Can't modify a person with an age that is over 100!")
        return "Not modified!"
    }

    if(gender == "Boy" || gender == "Girl") {

    }
    else {
        print("Gender has to be a girl or a boy!")
        return "Not modified!"
    }

    if(targetName != "" && targetName == self.name) {
        self.name = newName
        self.age = newAge
        self.gender = newGender

        print("You just changed \(oldName)'s gender from: \(oldGender) to: \(gender), \(oldName)'s name from: \(oldName) to: \(name) and \(oldName)'s age from: \(oldAge) to: \(age)!")
    }
    else {
        print("Please enter a valid target name or create one!")
    }

    return "Modified!"
}

func delete() -> String {
    return "Deleted!"
}
}

class Persons {
var personsDictionary = [String: Person]()
}

var persons = Persons()
var p1 = Person()
var p2 = Person()

p1.create("Isak", 11, "Boy")
p2.create("Sanne", 7, "Girl")

persons.personsDictionary[p1.name] = p1
persons.personsDictionary[p2.name] = p2

persons.personsDictionary["Isak"]?.delete()

这里我们有一个 Person 类(您在问题中定义的一个，但 delete() 方法略有更改)和一个具有 Dictionary 的 Persons 类[String : Person]。字典的键是你的人的名字，值是这个人。

当我们创建一个人实例时，我们将其存储在 personsDictionary 中，然后我们可以通过人名访问该字典中的每个人，并且将返回一个 Optional，我们可以在其上调用您定义的所有方法.