无法使用swift从json访问嵌套字典/数组

Question

我试图访问本地json文件的[“上类别”] [“第一类”] [0] [0]

{
    "upper category": {
        "first category": [
            [
                "this is a question", 
                "this is an answer", 
                "this is the rank"
            ], 
            [
                "this is a question2", 
                "this is an answer2", 
                "this is the rank2"
            ]
        ], 
        "second category": [
            [
                "this is a question3", 
                "this is an answer3", 
                "this is the rank3"
            ]
        ]
    }
}

同

let path = Bundle.main.path(forResource: "data", ofType: "json")
do {let data:NSData = try NSData(contentsOfFile: path!)
    let json = try? JSONSerialization.jsonObject(with: data as Data, options: JSONSerialization.ReadingOptions.mutableContainers) as AnyObject

我无法访问第一本字典以外的任何内容。

我尝试了几次选项（我试过多个较旧的解决方案，但它们似乎对我不起作用，也许很快3）

    if let description = ((((json?["upper category"] as? AnyObject)?["first category"] as? AnyObject)?[0] as? AnyObject)?[0] as? String) {

这可能是一个noob问题，我是ios的新手。 虽然任何答案都非常赞赏，解释如何为其他数量的嵌套类型编写代码是最好的

（xcode 8，swift 3）

Answer 1

这有点矫枉过正，但你可以将json转换为[String:[String:[[String]]]]

let json = try? JSONSerialization.jsonObject(...) as? [String:[String:[[String]]]]

否则，例如，如果字典包含嵌套字典以外的元素，则只需将顶级字典转换为[String:Any]并单独转换嵌套元素。

if let json = try? JSONSerialization.jsonObject(...) as? [String:Any] {

    let foo = json["foo"] as? Int
    let bar = json["bar"] as? [String:Any]

    ...
}