dictionaryToJSONString.swift

import UIKit
import AVFoundation

//Dictionary -> JSON String

let dictionary = ["aKey": "aValue", "anotherKey": "anotherValue"]

var theJSONText:String?

do {
    
    let theJSONData = try NSJSONSerialization.dataWithJSONObject(dictionary , options: NSJSONWritingOptions(rawValue: 0))
    
    
    theJSONText = String(data: theJSONData,
                               encoding: NSASCIIStringEncoding)
    
} catch let error as NSError {
    print(error.localizedDescription)
}