Convert Json string to Json object in Swift 4

The problem is that you thought your jsonString is a dictionary. It's not.

It's an array of dictionaries. In raw json strings, arrays begin with [ and dictionaries begin with {.

I used your json string with below code :

let string = "[{\"form_id\":3465,\"canonical_name\":\"df_SAWERQ\",\"form_name\":\"Activity 4 with Images\",\"form_desc\":null}]"let data = string.data(using: .utf8)!do {    if let jsonArray = try JSONSerialization.jsonObject(with: data, options : .allowFragments) as? [Dictionary<String,Any>]    {       print(jsonArray) // use the json here         } else {        print("bad json")    }} catch let error as NSError {    print(error)}

and I am getting the output :

[["form_desc": <null>, "form_name": Activity 4 with Images, "canonical_name": df_SAWERQ, "form_id": 3465]]

Using JSONSerialization always felt unSwifty and unwieldy, but it is even more so with the arrival of Codable in Swift 4. If you wield a [String:Any] in front of a simple struct it will ... hurt. Check out this in a Playground:

import Cocoalet data = "[{\"form_id\":3465,\"canonical_name\":\"df_SAWERQ\",\"form_name\":\"Activity 4 with Images\",\"form_desc\":null}]".data(using: .utf8)!struct Form: Codable {    let id: Int    let name: String    let description: String?    private enum CodingKeys: String, CodingKey {        case id = "form_id"        case name = "form_name"        case description = "form_desc"    }}do {    let f = try JSONDecoder().decode([Form].self, from: data)    print(f)    print(f[0])} catch {    print(error)}

With minimal effort handling this will feel a whole lot more comfortable. And you are given a lot more information if your JSON does not parse properly.

I tried the solutions here, and as? [String:AnyObject] worked for me:

do{    if let json = stringToParse.data(using: String.Encoding.utf8){        if let jsonData = try JSONSerialization.jsonObject(with: json, options: .allowFragments) as? [String:AnyObject]{            let id = jsonData["id"] as! String            ...        }    }}catch {    print(error.localizedDescription)}