Swift3 JSON解析 - 如何访问相关领域

Question

在访问从JSON在斯威夫特3所需的信息，这里就是我有实际困难：

override func viewDidLoad() 
{ 
    super.viewDidLoad() 

    let url = URL(string: "http://api.brewerydb.com/v2/beers?key=e3bdce7d0a80584c784cdc4b02459add&name=budweiser") 

    URLSession.shared.dataTask(with:url!) { (data, response, error) in 
     if error != nil { 
      print(error!) 

     } 
     else { 

      do { 

       let parsedData = try JSONSerialization.jsonObject(with: data!, options: JSONSerialization.ReadingOptions.mutableContainers) as AnyObject 
       // print(parsedData) 


       let dataLevel = parsedData["data"] as? NSDictionary 


       print(dataLevel) 

       let abv = dataLevel?["abv"] as? AnyObject 
       print(abv!) 




      } catch let error as NSError { 
       print(error) 
      } 
     } 

     }.resume() 
} 

override func didReceiveMemoryWarning() { 
    super.didReceiveMemoryWarning() 
    // Dispose of any resources that can be recreated. 
} 

}

链接到JSON文件在代码中 - 为什么我的代码没有返回'data'部分，我如何检索啤酒'name'，'abv'和'description'？

Answer 1

当你处理JSON我认为这是有帮助的使用工具，如： jsonformatter.curiousconcept.com 或 jsonlint.com 这帮助了我很多理解结构，什么样我处理的数据。

如果你看看你的JSON中，你可以注意到，埃里克绫说，数据是一个数组没有字典：

{ 
    "currentPage": 1, 
    "numberOfPages": 1, 
    "totalResults": 1, 
    "data": [{ 
     "id": "1P45iR", 
     "name": "Budweiser", 
     "nameDisplay": "Budweiser", 
     "description": "Known as \u201cThe King of Beers\u201d, Budweiser was first introduced by Adolphus Busch in 1876 and is brewed with the same high quality standards today. Budweiser is a medium-bodied, flavorful, crisp American-style lager, craft brewed with a blend of premium hop varieties, and associated with the core American values of celebration and optimism.", 
     "abv": "5", 
     "glasswareId": 5, 
     "srmId": 5, 
     "availableId": 1, 
     "styleId": 93, 
     "isOrganic": "N", 
     "labels": { 
      "icon": "https:\/\/s3.amazonaws.com\/brewerydbapi\/beer\/1P45iR\/upload_Y13vwL-icon.png", 
      "medium": "https:\/\/s3.amazonaws.com\/brewerydbapi\/beer\/1P45iR\/upload_Y13vwL-medium.png", 
      "large": "https:\/\/s3.amazonaws.com\/brewerydbapi\/beer\/1P45iR\/upload_Y13vwL-large.png" 
     }, 
     "status": "verified", 
     "statusDisplay": "Verified", 
     "servingTemperature": "cold", 
     "servingTemperatureDisplay": "Cold - (4-7C\/39-45F)", 
     "createDate": "2012-01-03 02:42:55", 
     "updateDate": "2016-03-21 19:54:11", 
     "glass": { 
      "id": 5, 
      "name": "Pint", 
      "createDate": "2012-01-03 02:41:33" 
     }, 
     "srm": { 
      "id": 5, 
      "name": "5", 
      "hex": "FBB123" 
     }, 
     "available": { 
      "id": 1, 
      "name": "Year Round", 
      "description": "Available year round as a staple beer." 
     }, 
     "style": { 
      "id": 93, 
      "categoryId": 8, 
      "category": { 
       "id": 8, 
       "name": "North American Lager", 
       "createDate": "2012-03-21 20:06:46" 
      }, 
      "name": "American-Style Lager", 
      "shortName": "American Lager", 
      "description": "Light in body and very light to straw in color, American lagers are very clean and crisp and aggressively carbonated. Flavor components should b e subtle and complex, with no one ingredient dominating the others. Malt sweetness is light to mild. Corn, rice, or other grain or sugar adjuncts are often used. Hop bitterness, flavor and aroma are negligible to very light. Light fruity esters are acceptable. Chill haze and diacetyl should be absent.", 
      "ibuMin": "5", 
      "ibuMax": "13", 
      "abvMin": "3.8", 
      "abvMax": "5", 
      "srmMin": "2", 
      "srmMax": "4", 
      "ogMin": "1.04", 
      "fgMin": "1.006", 
      "fgMax": "1.01", 
      "createDate": "2012-03-21 20:06:46", 
      "updateDate": "2015-04-07 15:39:26" 
     } 
    }], 
    "status": "success" 
} 

下面的代码工作，但我相信有一个更好的方式来得到abv用更少的代码：

override func viewDidLoad() 
    { 
     super.viewDidLoad() 

     let url = URL(string: "http://api.brewerydb.com/v2/beers?key=e3bdce7d0a80584c784cdc4b02459add&name=budweiser") 

     URLSession.shared.dataTask(with:url!) { (data, response, error) in 
      if error != nil { 
       print(error!) 

      } 
      else { 

       do { 

        let parsedData = try JSONSerialization.jsonObject(with: data!, options: JSONSerialization.ReadingOptions.mutableContainers) as? [String: Any] 


         let jsonArrayData = parsedData?["data"] as! NSArray 
         let data = jsonArrayData[0] as! NSDictionary 
         let abv = data["abv"] 
         print(abv)//Optional(5) in your case 


       } catch let error as NSError { 
        print(error) 
       } 
      } 

      }.resume() 
    }