無法從JSON訪問嵌套的字典/陣列，迅速

Question

我試圖訪問[ 「上限類別」] [ 「第一類」] [0] [0]本地JSON文件的

{ 
    "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" 
      ] 
     ] 
    } 
} 

與

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 

我無法訪問超出第一個字典的任何內容。

我試了幾次有類似的選項（我試過多箇舊的解決方案，但他們似乎並沒有爲我工作，也許迅疾3）

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

這可能是一個noob問題，我是新來的IOS。雖然任何答案非常讚賞，解釋如何編寫代碼，嵌套類型的其他數將是最好

（Xcode中8，快捷3）

Answer 1

這是一個有點矯枉過正，但你可以投的JSON來[String:[String:[[String]]]]

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