我试图通过比较另一个字典中的键来改变一个字典中的值。

Posted 2021-04-27

var clariQuestion: [String: String] = ["0": "What are my last 10 transactions",
                                    "1": "What are my spending transactions",
                                    "2": "What are my largest trasactions",
                                    "3": "What are my pending tracnstions"]

var explanationActionParameters: [String: Any] = ["clariQuestion": 2]

所以我需要将explanationActionParameters的值与clariQuestion的键匹配，然后当键匹配时，将explanationActionParameters中的数字2替换为 "what are my largest transactions"。令我感到困难的是，explanationActionParameter中的值是类型2，而clariQuestion中的键是类型String。我不知道该如何解决这个问题。

答案

你可以将你的int转换为字符串，使用 String(2) 或将你的字符串转换为int，比如 Int("2")我对你的回答是将你的clariQuestion字典转换成一个数组，因为键是整数，而数组可以看作是一个键是整数的字典。所以，你可以这样做

var clariQuestion: [String] = ["What are my last 10 transactions",
                                "What are my spending transactions",
                                "What are my largest trasactions",
                                "What are my pending tracnstions"]
var explanationActionParameters: [String: Any] = ["clariQuestion": 2]

let questionIndex = explanationActionParameters["clariQuestion"]
let question = clariQuestion[questionIndex]

如果你坚持维护这个字典结构，你可以 flatmap 你的字典，并将所有的键从字符串转换为int，就像这样。

clariQuestion.flatMap { (key, value) in [Int(key) : value] }

或者将所有的值转换为一个字符串，就像这样。

explanationActionParameters.flatMap { (key, value) in [key : String(value)] }

不管是哪种方式，现在你应该能够跨这些字典访问元素。我将创建一个函数来演示如何使用

func replace(_ clariQuestion: [String : String], _ explanationActionParameters: [String: Any]) -> [String: String] {
    // The dictionary that will be returned containing the mapping from clariQuestion to explanationActionParameters
    var ret = [String : String]()
    let mappedClariQuestion = clariQuestion.flatMap { (key, value) in [Int(key) : value] }
    for (key, value) in clariQuestion {
        ret[key] = mappedClariQuestion[value]
    }

    return ret
}

然后，只是 explanationActionParameters = replace(clariQuestion, explanationActionParameters)