JSON解码后如何访问多个NSDictionary

Question

在 JSONSerialization 解码并将as! 转换为 NSDictionary 后，获取以下数据。

{
    language = {
        A00001 = {
            chineseSimplified = CIMB;
            chineseTraditional = CIMB;
            english = CIMB;
            japanese = CIMB;
            korean = CIMB;
        };
    };
}

如何访问嵌套的 NSDictionary？

我能够通过data["language"] 获取一层数据，但我无法访问多个层，例如：

data["language"]["A00001"]["english"]
data["language"]?["A00001"]?["english"]?
data["language"]!["A00001"]!["english"]!

Xcode 返回此错误：

类型 'Any' 没有下标成员

参考类似问题： How to access deeply nested dictionaries in Swift Accessing Nested NSDictionary values in Swift 3.0 How do I manipulate nested dictionaries in Swift, e.g. JSON data?

Answer 1

尝试将其转换为 [String: [String: [String: String]]]，这是 Swift Dictionary 的嵌套结构。

let json = """
{
"language": {
    "A00001": {
        "chineseSimplified" : "CIMB",
        "chineseTraditional" : "CIMB",
        "english" : "CIMB",
        "japanese" : "CIMB",
        "korean" : "CIMB"
    }
    }
}
"""
if let jsonD = json.data(using: String.Encoding.utf8) {
    do {
        if let data = try JSONSerialization.jsonObject(with: jsonD, options: JSONSerialization.ReadingOptions.mutableLeaves) as? [String: [String: [String: String]]] {
            print(data["language"]!["A00001"]!["english"]!)
        }
    } catch let error {
        print(error.localizedDescription)
    }

}

这是另一个使用 Swift 4 的 Codable API 的答案。如果您的代码需要类型安全并且您确定 JSON 中的字段是一致的，我认为值得一试。

let json = """
{
"language": {
"A00001": {
"chineseSimplified" : "CIMB",
"chineseTraditional" : "CIMB",
"english" : "CIMB",
"japanese" : "CIMB",
"korean" : "CIMB"
}
}
}
"""
struct MyLanguages:Codable {
    struct LanguageGroup: Codable {
        struct Language:Codable {
            var chineseSimplified: String
            var chineseTraditional: String
            var english: String
            var japanese: String
            var korean: String
        }
        var A00001: Language

    }
    var language: LanguageGroup
}
if let jsonD = json.data(using: String.Encoding.utf8) {
    let jsonDecoder = JSONDecoder()
    do {
        let myLang = try jsonDecoder.decode(MyLanguages.self, from: jsonD)
        print(myLang.language.A00001.chineseSimplified)

    }
    catch let err {
        print(err.localizedDescription)
    }

}