Question

我有一个json字符串转换为字符串数组，如下所示：

    let str = "{ \"dtResult\": [ { \"itmdtl_item_no\": \"AO406705959SE3\" }, { \"itmdtl_item_no\": \"AO406708959SE3\" } ] }"
    let data = str.data(using: String.Encoding.utf8, allowLossyConversion: false)!

    do {
        let json = try JSONSerialization.jsonObject(with: data, options: []) as! [String: AnyObject]

        let result = json["dtResult"] as? [[String:Any]] ?? [ ]
        let item = result[0] as! [String:Any]

        print(item)

    } catch let error as NSError {
        print("Failed to load: \(error.localizedDescription)")
    }

当我打印出项目的结果时，我得到了这样的值：

[“itmdtl_item_no”：AO406705959SE3]

但我只想要字符串“AO406705959SE3”，我该怎么办？感谢。

Answer 1

首先不要写

let result = json["dtResult"] as? [[String:Any]] ?? [ ]

如果result为nil或为空，则应用会在result[0]上崩溃

而是写入以检查数组是否存在且不为空

if let result = json["dtResult"] as? [[String:Any]], !result.isEmpty {
   let item = result[0] as! [String:Any]
   // Now get the value for key "itmdtl_item_no"
   if let itemNo = item["itmdtl_item_no"] as? String {
       print(itemNo)
   }
}

Swift3从数组中获取元素

1 个答案: