快速SwiftyJSON获得价值

Question

I have a json string: let jsonStr = {"username":"Jame"} , and I use swiftyJson: let json = JSON(jsonStr) . Now I want to get the username, so I try json["username"].string , but the result is nil.

Answer 1

First, You should use

let jsonStr = "{\\"username\\":\\"Jame\\"}"

instead of

let jsonStr = {"username":"Jame"}

If jsonStr is just String, you need to convert String to Dictionary. JSON initializer requires instance of Dictionary. try this:

let jsonStr = "{\"username\":\"Jame\"}" // string
let jsonData = jsonStr.dataUsingEncoding(NSUTF8StringEncoding)! // string->NSData
let jsonDic = try! NSJSONSerialization.JSONObjectWithData(jsonData, options: .AllowFragments) // NSData->Dictionary
let json = JSON(jsonDic) // good!
print(json)
let name = json["username"].string
print(name) // Optional("Jame")

More safely, you use if let , do{} catch(let e){} instead of ! , try!