SwiftyJSON - expression is ambiguous - ios

Question

I try to parse JSON using SwiftyJSON but I face a problem.
I use tutorial from here
Here is my code
var JSONStorage : [Article?]?
var objects = [[String: String]]()
override func viewDidLoad() {
super.viewDidLoad()
let number = arc4random_uniform(1000)
let urlString = "http://78.27.190.58:3200/api/get_article/17?\(number)"
if let url = NSURL(string: urlString) {
if let data = try? NSData(contentsOfURL: url, options: []) {
let json = JSON(data: data)
for element in json["article"].arrayValue {
let id = Int(element["id"].stringValue)
let title = element["title"].stringValue
let subtitle = element["subtitle"].stringValue
let body = element["body"].stringValue
let img = element["images"]["main"].rawValue
let obj = ["id": id, "title": title, "subtitle": subtitle, "body": body, "img": img]
objects.append(obj)
}
}
}
}
here is the error I got
What am I doing wrong ?

Answer 1

Your objects is of type [[String:String]], an array of dictionaries. These dictionaries are typed String for the key and String for the value.
But you add to this array a dictionary containing different types of values: Strings with your .stringValue objects, and a .rawValue one which must be of type NSData I presume.
A solution could be to type your dictionary [String:AnyObject] (and thus your array [[String:AnyObject]]) and to typecast on the other side when retrieving the values.
By the way, the compiler says "expression is ambiguous" because it failed at inferring the type of the array (and now we know why).
Note that it's not the most efficient when parsing JSON. A better way would be to create objects from your data: classes or structs. You could have a struct Article to hold each element values for example, like you showed in another question.

Answer 2

Arrays or Dictionaries in swift can not be heterogeneous. If you look at your code you want to put one int and four strings as values of obj.
This will work:
for element in json["article"].arrayValue {
let id = element["id"].stringValue // must be string to put it in obj
let title = element["title"].stringValue
let subtitle = element["subtitle"].stringValue
let body = element["body"].stringValue
let img = element["images"]["main"].rawValue
let obj: [String: String] = ["id": id, "title": title, "subtitle": subtitle, "body": body, "img": img]
objects.append(obj)
}