在Swift 4中解析JSON

我正在开发一个应用程序，从NiceHash api中获得平衡。我必须处理的JSON如下所示：

{
   "result":{
      "stats":[
         {
            "balance":"0.00000124",
            "rejected_speed":"0",
            "algo":5,
            "accepted_speed":"0"
         },
         {
            "balance":"0.00000163",
            "rejected_speed":"0",
            "algo":7,
            "accepted_speed":"0"
         },
         {
            "balance":"0.00114271",
            "rejected_speed":"0",
            "algo":8,
            "accepted_speed":"0.0002237"
         },
         {
            "balance":"0.00009395",
            "rejected_speed":"0",
            "algo":14,
            "accepted_speed":"0"
         },
         {
            "balance":"0.0000097",
            "rejected_speed":"0",
            "algo":20,
            "accepted_speed":"0"
         },
         {
            "balance":"0.00000004",
            "rejected_speed":"0",
            "algo":21,
            "accepted_speed":"0"
         },
         {
            "balance":"0.00128791",
            "rejected_speed":"0",
            "algo":22,
            "accepted_speed":"0"
         },
         {
            "balance":"0.0000005",
            "rejected_speed":"0",
            "algo":23,
            "accepted_speed":"0"
         },
         {
            "balance":"0.00310707",
            "rejected_speed":"0",
            "algo":24,
            "accepted_speed":"0.0000002"
         },
         {
            "balance":"0.00002411",
            "rejected_speed":"0",
            "algo":26,
            "accepted_speed":"0"
         },
         {
            "balance":"0.00000007",
            "rejected_speed":"0",
            "algo":27,
            "accepted_speed":"0"
         },
         {
            "balance":"0.0000047",
            "rejected_speed":"0",
            "algo":28,
            "accepted_speed":"0"
         },
         {
            "balance":"0.00001291",
            "rejected_speed":"0",
            "algo":29,
            "accepted_speed":"0"
         }
      ],
      "payments":[

      ],
      "addr":"some_bitcoin_adress"
   },
   "method":"stats.provider"
}

struct stats: Codable {
    let balance: String
    let rejected_speed: String
    let algo: String
    let accepted_speed: String
}
struct result: stats {
    let stats: stats
}

我想对“balance”的所有值求和，但我不确定如何访问它。我现在的代码如下所示：

{
   "result":{
      "stats":[
         {
            "balance":"0.00000124",
            "rejected_speed":"0",
            "algo":5,
            "accepted_speed":"0"
         },
         {
            "balance":"0.00000163",
            "rejected_speed":"0",
            "algo":7,
            "accepted_speed":"0"
         },
         {
            "balance":"0.00114271",
            "rejected_speed":"0",
            "algo":8,
            "accepted_speed":"0.0002237"
         },
         {
            "balance":"0.00009395",
            "rejected_speed":"0",
            "algo":14,
            "accepted_speed":"0"
         },
         {
            "balance":"0.0000097",
            "rejected_speed":"0",
            "algo":20,
            "accepted_speed":"0"
         },
         {
            "balance":"0.00000004",
            "rejected_speed":"0",
            "algo":21,
            "accepted_speed":"0"
         },
         {
            "balance":"0.00128791",
            "rejected_speed":"0",
            "algo":22,
            "accepted_speed":"0"
         },
         {
            "balance":"0.0000005",
            "rejected_speed":"0",
            "algo":23,
            "accepted_speed":"0"
         },
         {
            "balance":"0.00310707",
            "rejected_speed":"0",
            "algo":24,
            "accepted_speed":"0.0000002"
         },
         {
            "balance":"0.00002411",
            "rejected_speed":"0",
            "algo":26,
            "accepted_speed":"0"
         },
         {
            "balance":"0.00000007",
            "rejected_speed":"0",
            "algo":27,
            "accepted_speed":"0"
         },
         {
            "balance":"0.0000047",
            "rejected_speed":"0",
            "algo":28,
            "accepted_speed":"0"
         },
         {
            "balance":"0.00001291",
            "rejected_speed":"0",
            "algo":29,
            "accepted_speed":"0"
         }
      ],
      "payments":[

      ],
      "addr":"some_bitcoin_adress"
   },
   "method":"stats.provider"
}

struct stats: Codable {
    let balance: String
    let rejected_speed: String
    let algo: String
    let accepted_speed: String
}
struct result: stats {
    let stats: stats
}

以及获取JSON的函数：

func updateBalance() {
    let sampleDataAdress = "nicehash_link_here"
    let url URL(string: sampleDataAdress)!
    let jsonSata = try! Data(contentsOf: url)
    let jsonDecoder = JSONDecoder()
    let data = try? jsonDecoder.decode(Array<stats>.self, from jsonData)
    data?.count
    dump(data?.first)
}

func updateBalance（）{
让SampleDataAddress=“niceshash\u链接\u此处”
让url（字符串：SampleDataAddress）！
让jsondata=try！数据（contentsOf:url）
让jsonDecoder=jsonDecoder（）
让data=try？jsonDecoder.decode（Array.self，来自jsonData）
数据？计数
转储（数据？.first）
}

---

我希望我至少能得到第一个数据，但我得到的却是零。这是我第一次在Swift 4中使用JSON，我想这段代码只是垃圾。

有很多问题

---

首先，为了避免混淆，结构的名称总是大写的。但是，您的

stats

struct包含的混乱不仅仅是命名。以大写字母开始命名结构是Swift命名惯例。顺便说一句，您应该使用URLSession异步下载json数据。如果您对algo属性使用了错误的类型，那么它应该是Int而不是字符串。您应该添加结构，该结构的名称为“Response”，并且该结构必须包含“result”结构的属性。最后，使用jsonDecoder.decode（Response.self，来自jsonData）而不是jsonDecoder.decode（Array.self，来自jsonData）解析“Response”结构，而不是使用

try？

忽略抛出的错误，在do catch块中使用

try

，并打印抛出的错误。它会确切地告诉您问题是什么。为什么不可编码？似乎这些对象永远不会被编码。您还可以向Result

var sum:Double{return stats.flatMap{Double（$0.balance）}.reduce（0，+）}

添加一个计算属性，类似吗

.0

它不是needed@LeoDabus我知道这一点，但为了更好的可读性，我总是使用正确的文本类型。