我怎样才能做一个 swift 多题测验，这样问题就不会重复了？

Question

我没有任何编程经验。几个月来，我一直在看 youtube 视频。如果有人可以帮助我，我将非常感激。当我运行使用模拟器的代码时，它会在出现下一个新问题之前多次重复问题。我希望它运行这样它只提出一个问题而不是一遍又一遍地重复同一个问题。请在下面找到代码。

import UIKit

class ViewController: UIViewController {

    @IBOutlet weak var QuestionLabel: UILabel!

    @IBOutlet weak var Button1: UIButton!

    @IBOutlet weak var Button2: UIButton!

    @IBOutlet weak var Button3: UIButton!

    @IBOutlet weak var Button4: UIButton!

    @IBOutlet weak var Next: UIButton!

    @IBOutlet weak var LabelEnd: UILabel!
    var CorrectAnswer = String()


    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        Hide()
        RamdomQuestions()
    }

    func RamdomQuestions () {
        var RandomNumber = arc4random() % 4
        RandomNumber += 1

        switch (RandomNumber) {

        case 1:
            QuestionLabel.text = "Hola familia, Cual es mi nombre? "
            Button1.setTitle ("Cesar", forState: UIControlState.Normal)
            Button2.setTitle ("Karlos", forState: UIControlState.Normal)
            Button3.setTitle ("William", forState: UIControlState.Normal)
            Button4.setTitle ("Chiqui", forState: UIControlState.Normal)
            CorrectAnswer = "2"

            break
        case 2:
            QuestionLabel.text = "Hola famili, cual es mi apellido? "
            Button1.setTitle ("Perez", forState: UIControlState.Normal)
            Button2.setTitle ("Carvajal", forState: UIControlState.Normal)
            Button3.setTitle ("Garcia", forState: UIControlState.Normal)
            Button4.setTitle ("Sanchez", forState: UIControlState.Normal)
            CorrectAnswer = "1"

            break
        case 3:
            QuestionLabel.text = "Quien hace la lachona mas rica? "
            Button1.setTitle ("Willy", forState: UIControlState.Normal)
            Button2.setTitle ("Mario", forState: UIControlState.Normal)
            Button3.setTitle ("Karlos", forState: UIControlState.Normal)
            Button4.setTitle ("Juan David", forState: UIControlState.Normal)
            CorrectAnswer = "1"

            break
        case 4:
            QuestionLabel.text = "Quien hace las tartas mas lindas"
            Button1.setTitle ("Jili", forState: UIControlState.Normal)
            Button2.setTitle ("Carvajal", forState: UIControlState.Normal)
            Button3.setTitle ("Garcia", forState: UIControlState.Normal)
            Button4.setTitle ("Leidy y Liz", forState: UIControlState.Normal)
            CorrectAnswer = "4"

            break

        default:
            break
        }
    }

    func Hide (){
        LabelEnd.hidden = true
        Next.hidden = true
    }

    func UnHide () {
        LabelEnd.hidden = false
        Next.hidden = false
    }

    @IBAction func Button1Action(sender: AnyObject) {
        UnHide()
        if (CorrectAnswer == "1") {
            LabelEnd.text = "Correcto"
        }
        else{
            LabelEnd.text = "Falso"
        }
    }

    func Button2Action(sender: AnyObject) {
        UnHide()
        if (CorrectAnswer == "2") {
            LabelEnd.text = "Correcto"

        }
        else{
            LabelEnd.text = "Falso"
        }
    }

    func Button3Action(sender: AnyObject) {
        UnHide()
        if (CorrectAnswer == "3") {
            LabelEnd.text = "Correcto"
        }
        else{
            LabelEnd.text = "Falso"
        }
    }

    func Button4Action(sender: AnyObject) {
        UnHide()
        if (CorrectAnswer == "4") {
            LabelEnd.text = "Correcto"
        }
        else{
            LabelEnd.text = "Falso"
        }
    }

    @IBAction func Next(sender: AnyObject) {
        RamdomQuestions()
    }
}

Answer 1

试试下面的代码，希望它对你有用

class ViewController: UIViewController {

@IBOutlet weak var QuestionLabel: UILabel!
@IBOutlet weak var Button1: UIButton!
@IBOutlet weak var Button2: UIButton!
@IBOutlet weak var Button3: UIButton!
@IBOutlet weak var Button4: UIButton!
@IBOutlet weak var Next: UIButton!
@IBOutlet weak var LabelEnd: UILabel!

var CorrectAnswer = String()
var randomQuestionArray:[Int] = [1, 2, 3, 4]

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.

    Hide()
    RamdomQuestions()
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

func RamdomQuestions () {

    let randomIndex = Int(arc4random_uniform(UInt32(randomQuestionArray.count)))

    if randomQuestionArray.count > 0 {

    switch (randomQuestionArray[randomIndex]) {

    case 1:
        QuestionLabel.text = "Hola familia, Cual es mi nombre? "
        Button1.setTitle ("Cesar", forState: UIControlState.Normal)
        Button2.setTitle ("Karlos", forState: UIControlState.Normal)
        Button3.setTitle ("William", forState: UIControlState.Normal)
        Button4.setTitle ("Chiqui", forState: UIControlState.Normal)
        CorrectAnswer = "2"
        break

    case 2:
        QuestionLabel.text = "Hola famili, cual es mi apellido? "
        Button1.setTitle ("Perez", forState: UIControlState.Normal)
        Button2.setTitle ("Carvajal", forState: UIControlState.Normal)
        Button3.setTitle ("Garcia", forState: UIControlState.Normal)
        Button4.setTitle ("Sanchez", forState: UIControlState.Normal)
        CorrectAnswer = "1"
        break

    case 3:
        QuestionLabel.text = "Quien hace la lachona mas rica? "
        Button1.setTitle ("Willy", forState: UIControlState.Normal)
        Button2.setTitle ("Mario", forState: UIControlState.Normal)
        Button3.setTitle ("Karlos", forState: UIControlState.Normal)
        Button4.setTitle ("Juan David", forState: UIControlState.Normal)
        CorrectAnswer = "1"
        break

    case 4:
        QuestionLabel.text = "Quien hace las tartas mas lindas"
        Button1.setTitle ("Jili", forState: UIControlState.Normal)
        Button2.setTitle ("Carvajal", forState: UIControlState.Normal)
        Button3.setTitle ("Garcia", forState: UIControlState.Normal)
        Button4.setTitle ("Leidy y Liz", forState: UIControlState.Normal)
        CorrectAnswer = "4"
        break

    default:
        break

    }
        randomQuestionArray.removeAtIndex(randomIndex)
    }


}

func Hide () {
    LabelEnd.hidden = true
    Next.hidden = true
}

func UnHide () {
    LabelEnd.hidden = false
    Next.hidden = false
}

@IBAction func Button1Action(sender: AnyObject) {
    UnHide()
    if (CorrectAnswer == "1") {
        LabelEnd.text = "Correcto"
    } else{
        LabelEnd.text = "Falso"
    }
}

func Button2Action(sender: AnyObject) {
    UnHide()
    if (CorrectAnswer == "2") {
        LabelEnd.text = "Correcto"
    } else{
        LabelEnd.text = "Falso"
    }
}

func Button3Action(sender: AnyObject) {
    UnHide()
    if (CorrectAnswer == "3") {
        LabelEnd.text = "Correcto"
    } else{
        LabelEnd.text = "Falso"
    }
}

func Button4Action(sender: AnyObject) {
    UnHide()
    if (CorrectAnswer == "4") {
        LabelEnd.text = "Correcto"
    } else{
        LabelEnd.text = "Falso"
    }
}

@IBAction func Next(sender: AnyObject) {
    RamdomQuestions()
}

}

Answer 2

这个问题的典型解决方案是有一个问题数组（或模型中的索引），然后随机排列这个数组，使其随机。然后您可以遍历这些随机排列的问题，它们将以随机方式出现，但您不必担心它们会再次出现。

在 Swift 4.2 中，您将使用内置的 shuffle 或 shuffled 方法来打乱数组。

4.2之前的Swift版本，需要自己对数组进行shuffle。请注意，生成随机数时，不应将 arc4random 与 % 运算符一起使用。这就引入了 modulo bias. Instead, use arc4random_uniform which generates uniformly distributed random numbers within a range of values. And shuffling the array, you should use a Fisher-Yates algorithm, which eliminates some subtle biases introduced by naive shuffling algorithms. For general information, see the Fisher-Yates article in Wikipedia. For specific Swift implementation, see How do I shuffle an array in Swift?。无论如何，算法看起来像：

extension MutableCollection {

    /// Shuffle the elements of `self` in-place.

    mutating func shuffle() {
        if count < 2 { return }    // empty and single-element collections don't shuffle

        for i in 0 ..< count - 1 {
            let j = Int(arc4random_uniform(UInt32(count - i)))
            if j != 0 {
                let current = index(startIndex, offsetBy: i)
                let swapped = index(current, offsetBy: j)
                swapAt(current, swapped)
            }
        }
    }

    /// Return shuffled collection the elements of `self`.

    func shuffled() -> Self {
        var results = self
        results.shuffle()
        return results
    }

}

然后您可以像这样使用它：

var questionIndexes = Array(0 ..< questions.count)  // builds an array [0, 1, 2, ... n-1], where _n_ is the number of questions
questionIndexes.shuffle()                           // shuffle that list

你最终得到一个数字 0 到 n-1 的数组，这些数字被打乱（即以随机顺序出现，但没有数字出现超过一次）。您现在可以遍历这个 questionIndexes 数组，每个问题将被问一次且仅一次，但它们将以随机顺序呈现。

一些不相关的观察结果：

您可能希望采用 Cocoa 命名约定，即该方法和属性名称应始终以小写字母开头。只有数据类型（例如类或结构）和枚举以大写字母开头。
在Swift中执行switch语句时，不需要break。 Swift 不会像 Objective-C 那样失败。当我解决下面的第 5 点时，结果我最终完全分解了 switch 语句，但为了您将来的参考，您不需要在每个 [= 的末尾 break 25=] 在 Swift 中就像你在基于 C 的编程语言中所做的那样 Objective-C。事实上，如果您希望 Swift case 语句进入下一个语句，就像在 Objective-C 中那样，您必须使用 fallthrough 关键字。
您可能不应该将 correctAnswer 初始化为 String()。只需将其声明为可选（如果需要，可以隐式解包）。
更好的是，correctAnswer 应该是 Int 而不是 String。我还会使用从零开始的值，以便我可以轻松地查找该值以确认是否按下了正确的按钮。
这是一个更高级的主题，但我建议将 "model"（即关于问题文本、潜在答案和正确答案的数据）与 "controller" 分开（从模型中获取信息并更新视图的代码）。这是我们在应用程序中使用的 model-view-controller 范例的一部分。它使您的应用程序在未来更易于维护（例如，您可以添加更多问题、更改问题等，但不必接触视图控制器中的代码）。它还支持更灵活的模式（例如，问题和答案可以由远程 Web 服务提供或存储在数据库中）。

例如，您可能有一个类型可以捕获问题及其可能的答案，并确定哪个是正确答案。
```
struct Question {
    let question: String
    let answers: [String]
    let correctAnswer: Int
}
```
您的模型可能包含 Question 个对象的数组：
```
var questions: [Question] = [
    Question(
        question: "Hola familia, Cual es mi nombre?",
        answers: ["Cesar", "Karlos", "William", "Chiqui"],
        correctAnswer: 1),
    Question(
        question: "Hola famili, cual es mi apellido?",
        answers: ["Perez", "Carvajal", "Garcia", "Sanchez"],
        correctAnswer: 0),
    Question(
        question: "Quien hace la lachona mas rica?",
        answers: ["Willy", "Mario", "Karlos", "Juan David"],
        correctAnswer: 2),
    Question(
        question: "Quien hace las tartas mas lindas?",
        answers: ["Jili", "Carvajal", "Garcia", "Leidy y Liz"],
        correctAnswer: 3)
]
```
请注意，请原谅我将这些问题中的 "correct answer" 更改为您问题中的内容。我只是想说明我们正在处理从 0 到 3 的数字（不是 1 到 4）。

将所有这些放在一起，您的实现可能如下所示：

import UIKit

struct Question {
    let question: String
    let answers: [String]
    let correctAnswer: Int
}

class ViewController: UIViewController {

    @IBOutlet weak var questionLabel: UILabel!

    @IBOutlet weak var button1: UIButton!
    @IBOutlet weak var button2: UIButton!
    @IBOutlet weak var button3: UIButton!
    @IBOutlet weak var button4: UIButton!

    lazy var buttons: [UIButton] = { return [self.button1, self.button2, self.button3, self.button4] }()

    @IBOutlet weak var nextButton: UIButton!

    @IBOutlet weak var endLabel: UILabel!

    var questions: [Question] = [
        Question(
            question: "Hola familia, Cual es mi nombre?",
            answers: ["Cesar", "Karlos", "William", "Chiqui"],
            correctAnswer: 1),
        Question(
            question: "Hola famili, cual es mi apellido?",
            answers: ["Perez", "Carvajal", "Garcia", "Sanchez"],
            correctAnswer: 0),
        Question(
            question: "Quien hace la lachona mas rica?",
            answers: ["Willy", "Mario", "Karlos", "Juan David"],
            correctAnswer: 2),
        Question(
            question: "Quien hace las tartas mas lindas?",
            answers: ["Jili", "Carvajal", "Garcia", "Leidy y Liz"],
            correctAnswer: 3)
    ]

    var questionIndexes: [Int]!
    var currentQuestionIndex = 0

    override func viewDidLoad() {
        super.viewDidLoad()

        questionIndexes = Array(0 ..< questions.count)  // builds an array [0, 1, 2, ... n]
        questionIndexes.shuffle()                       // randomizes that list

        updateLabelsAndButtonsForIndex(0)
    }

    func updateLabelsAndButtonsForIndex(questionIndex: Int) {
        // if we're done, show message in `endLabel` and hide `nextButton`

        guard questionIndex < questions.count else {
            endLabel.hidden = false
            endLabel.text = "All done!"
            nextButton.hidden = true
            return
        }

        // update our property

        currentQuestionIndex = questionIndex

        // hide end label and next button

        hideEndLabelAndNextButton()

        // identify which question we're presenting

        let questionObject = questions[questionIndexes[questionIndex]]

        // update question label and answer buttons accordingly

        questionLabel.text = questionObject.question
        for (answerIndex, button) in buttons.enumerate() {
            button.setTitle(questionObject.answers[answerIndex], forState: .Normal)
        }
    }

    func hideEndLabelAndNextButton() {
        endLabel.hidden = true
        nextButton.hidden = true
    }

    func unhideEndLabelAndNextButton() {
        endLabel.hidden = false
        nextButton.hidden = false
    }

    // note, because I created that array of `buttons`, I now don't need
    // to have four `@IBAction` methods, one for each answer button, but 
    // rather I can look up the index for the button in my `buttons` array
    // and see if the index for the button matches the index of the correct
    // answer.

    @IBAction func didTapAnswerButton(button: UIButton) {
        unhideEndLabelAndNextButton()

        let buttonIndex = buttons.indexOf(button)
        let questionObject = questions[questionIndexes[currentQuestionIndex]]

        if buttonIndex == questionObject.correctAnswer {
            endLabel.text = "Correcto"
        } else {
            endLabel.text = "Falso"
        }
    }

    @IBAction func didTapNextButton(sender: AnyObject) {
        updateLabelsAndButtonsForIndex(currentQuestionIndex + 1)
    }

}

里面隐藏了很多东西，所以如果您不完全了解这里发生的一切，我不会担心细节。但关键是，在你的模型中建立一个索引数组，打乱它，然后你可以继续遍历这个打乱的数组，你保证你不会问同样的问题两次。

Answer 3

我最初连接了

@IBAction func didTapAnswerButton(button:

和

@IBAction func didTapNextButton(sender:

五个按钮，模拟器没有在屏幕上显示正确或错误。

我又试了一次，刚连接

@IBAction func didTapAnswerButton(button:

五个按钮和

@IBAction func didTapNextButton(sender:

单击“下一步”按钮，它起作用了。

我怎样才能做一个 swift 多题测验，这样问题就不会重复了？

How can I make a swift multiple questions quiz so the questions do not repeat themselves?

ios

swift

random

arc4random