ios - 如何在调用索引后从数组中永久删除项目？

Question

我的以下代码通过从字典中创建一个键和值数组并确保两个数组具有相同的索引来显示一个问题及其匹配的答案。但是，在随机选择一个问题及其答案后，我想将它们从各自的数组中永久删除，直到显示数组中的所有其他项目。简而言之，我如何确保在显示所有项目或直到用户回答错误之前不会再次显示问题和答案集？截至目前，当我想确保它根本不会显示两次时，我的代码只会确保不会连续两次选择相同的随机索引。

这是我的代码(适用于 iOS 的 swift):

func randomQuestion() {


    //random question
    var questionList = Array(QADictionary.keys)
    var rand = Int(arc4random_uniform(UInt32(questionList.count)))
    questionLabel.text = questionList[rand]




    //matching answers
    var answerList = Array(QADictionary.values)
    var choices = answerList[rand]




        rightAnswerBox = arc4random_uniform(4)+1

        //create button
        var button:UIButton = UIButton()
        var x = 1



        for index in 1...4
        {

            button = view.viewWithTag(index) as! UIButton

            if (index == Int(rightAnswerBox))
            {
                button.setTitle(choices[0], for: .normal)

            }

            else {
                button.setTitle(choices[x], for: .normal)
                x += 1

            }

            func removePair() {
                questionList.remove(at: rand)
                answerList.remove(at: rand)


            }


            randomImage()

        }
    }


let QADictionary = ["Who is Thor's brother?" : ["Atum", "Loki", "Red Norvell", "Kevin Masterson"], "What is the name of Thor's hammer?" : ["Mjolinr", "Uru", "Stormbreaker", "Thundara"], "Who is the father of Thor?" : ["Odin", "Sif", "Heimdall", "Balder"]]

Answer 1

将您的 questionList 移动到 viewController 的一个属性，以便它从 randomQuestion 的一次调用到下一次调用保持不变。只有在它为空时才重新加载它。

使用字典查找匹配的答案，而不是使用第二个数组。

var questionList = [String]()

func randomQuestion() {

    //if no more questions, reload the questionList
    if questionList.isEmpty {
        questionList = Array(QADictionary.keys)
    }

    var rand = Int(arc4random_uniform(UInt32(questionList.count)))
    questionLabel.text = questionList[rand]

    //matching answers
    var choices = QADictionary[questionList[rand]]!

    questionList.remove(at: rand)

    rightAnswerBox = arc4random_uniform(4)+1

    //create button
    var button:UIButton = UIButton()
    var x = 1

    for index in 1...4
    {
        button = view.viewWithTag(index) as! UIButton

        if (index == Int(rightAnswerBox))
        {
            button.setTitle(choices[0], for: .normal)

        }
        else {
            button.setTitle(choices[x], for: .normal)
            x += 1

        }

        func removePair() {
            questionList.remove(at: rand)
        }

        randomImage()
    }
}