Int不能转换为Dictionary< string，string>

问题描述：

此行出现错误（questionField.text = listOfQuestionsAndAnswers [currentQuestionIndex]）（Int不能转换为Dictionary）。
此外，我想让所有问题逐一显示，最后一个问题之后，谁是保罗应该再次显示...

There is an error at this line (questionField.text = listOfQuestionsAndAnswers[currentQuestionIndex]) (Int is not convertible to Dictionary). Moreover, I want all the questions to be displayed one-by-one, and after the last question, "Who's is Paul" should be displayed again...

let listOfQuestionsAndAnswers = ["Who’s Paul?": "An American", "Who’s Joao?": "A Bresilian", "Who’s Riccardo?": "An Italian"]

@IBAction func answerButtonTapped (sender: AnyObject){

    for (Question, rightAnswer) in listOfQuestionsAndAnswers {

        questionField.text = listOfQuestionsAndAnswers[currentQuestionIndex]
        if currentQuestionIndex <= listOfQuestionsAndAnswers.count
        {
            currentQuestionIndex = (++currentQuestionIndex) % listOfQuestionsAndAnswers.count
            answerBut.setTitle("ANSWER", forState: UIControlState.Normal)
        }
        else
        {
            (sender as UIButton).userInteractionEnabled = false
        }
    }
}

我得到了错误Int不能转换为DictionaryIndex，我不明白这是什么意思。我不能通过索引访问我的字典。

I am getting the error Int is not convertible to DictionaryIndex and I don't understand what that means. Shouldn't I be able to access my dictionary by index.

答

你不能用诠释。词典包含键和值，并由键下标。在这种情况下，您的 listOfQuestionsAndAnswers 是一个字典，键和值都是字符串。

You can't subscript a dictionary by Int. Dictionaries contain keys and values and are subscripted by the key. In this case your listOfQuestionsAndAnswers is a Dictionary where the keys and values are both Strings.

如果要下标通过Int，考虑使用（String，String）元组的数组。

If you wanted to subscript by Int, consider using an array of (String, String) tuples.

如果要使用字典，您必须通过其键值从字典获取值：

If you want to use a dictionary, you have to retrieve the value from the dictionary by its key:

listOfQuestionsAndAnswers["Who’s Paul?"] // "An American"

Int不能转换为Dictionary< string，string>

相关推荐