Tuesday, August 30, 2016

How to parse JSON using JSONSerialization in Swift 3

Sample code in swift 3 (Xcode 8 beta 6) with Swift 2 code shown beneath
samplecode.swift   Select all
import Foundation let str1 = "{\"names\": [\"Bob\", \"Tim\", \"Tina\"]}" let str2 = "{\"names\": [\"Bob2\", \"Tim2\", \"Tina2\"]};" for str in [str1, str2] { let data = str.data(using: String.Encoding.utf8) // let data = str.dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: false) // Swift 2 do { let json = try JSONSerialization.jsonObject(with: data!) as! [String: AnyObject] // let json = try NSJSONSerialization.JSONObjectWithData(data!, options: []) // Swift 2 print(json) if let names = json["names"] as? [String] { print(names) } } catch let error as NSError { print(str) print("Failed to load: \(error.localizedDescription)") } }



Sample Code with json from url in swift 3 (Xcode 8 beta 6) with Swift 2 code shown beneath
samplecode.swift   Select all
import Foundation struct Video { var name: String var url: String } var musicvideo:[Video]=[] typealias JSONDictionary = [String: AnyObject] typealias JSONArray = Array<AnyObject> let url = Foundation.URL(string: "https://itunes.apple.com/us/rss/topmusicvideos/limit=3/json") //let url = NSURL(string: "https://itunes.apple.com/us/rss/topmusicvideos/limit=3/json") // Swift 2 do { let data = try Data(contentsOf: url!) // let data = NSData(contentsOfURL: url!) // Swift 2 let json = try JSONSerialization.jsonObject(with: data, options: .allowFragments) as! JSONDictionary // .allowFragments - top level object is not Array nor Dictionary. // let json = try NSJSONSerialization.JSONObjectWithData(data!, options: .AllowFragments) // Swift 2 if let feed = json["feed"] as? JSONDictionary, let entries = feed["entry"] as? JSONArray { // entries = feed["entry"] as? JSONArray { // Swift 2 //print(entries) for (index, entry) in entries.enumerated() { // for (index, entry) in entries.enumerate() { // Swift 2 //print("\(index) is \(entry)") if let name = entry["im:name"] as? JSONDictionary, let vName = name["label"] as? String, // SE-0099 XCode 8 beta 4 // vName = name["label"] as? String, // Swift 2 let video = entry["link"] as? JSONArray, // SE-0099 XCode 8 beta 4 // video = entry["link"] as? JSONArray, // Swift 2 let vUrl = video[1] as? JSONDictionary, // SE-0099 XCode 8 beta 4 // vUrl = video[1] as? JSONDictionary, // Swift 2 let vHref = vUrl["attributes"] as? JSONDictionary, // SE-0099 XCode 8 beta 4 // vHref = vUrl["attributes"] as? JSONDictionary, // Swift 2 let vVideoUrl = vHref["href"] as? String // SE-0099 XCode 8 beta 4 // vVideoUrl = vHref["href"] as? String // Swift 2 { print(vName) print(vVideoUrl) musicvideo.append(Video(name: vName, url:vVideoUrl)) } } } } catch let error as NSError { print("Failed to load: \(error.localizedDescription)") } let jsonDict = musicvideo.map { return ["name":$0.name, "url":$0.url]} print(jsonDict)



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