jsonDictionary.swift

extension NSDictionary {
    convenience init ? (json: String) {
        if let data = (try? JSONSerialization.jsonObject(with: json.data(using: String.Encoding.utf8, allowLossyConversion: true)!, options: .mutableContainers)) as? NSDictionary {
            self.init(dictionary: data)
        } else {
            self.init()
            return nil
        }
    }
    
    func formatJSON() -> String? {
        if let jsonData = try? JSONSerialization.data(withJSONObject: self, options: []) {
            let jsonStr = String(data: jsonData, encoding: .utf8)
            return jsonStr
        }
        return nil
    }
}