Passing instance variables to other classes

override func viewDidLoad() {
    super.viewDidLoad()


    func retrieveData(url1: String) {

        var testData = webConnect()
        testData.callArray()
        testData.downloadData(url1)

        println(testData.mutableArray1)
        println (testData.mutableArray)

    }

    retrieveData("$SOMEURL$")
}

var mutableArray: NSMutableArray = []
var mutableArray1: NSMutableArray = []

override init()
{
    super.init()
    var configuration = NSURLSessionConfiguration.defaultSessionConfiguration()
    mainSession = NSURLSession(configuration: configuration,
        delegate: self,
        delegateQueue:NSOperationQueue.mainQueue())
}

func URLSession(session: NSURLSession, downloadTask: NSURLSessionDataTask, didFinishDownloadingToURL location: NSURL)   {
    var locateData: NSData

    locateData = NSData(contentsOfURL: location)!
    var testArray: NSMutableArray = ["wer","werwer"]
    testArray = ["blah", "blah"]
    self.mutableArray1 = testArray
}

func downloadData(URLString: String)     {
    var request = NSMutableURLRequest(URL: NSURL(string: URLString)!)
    request.HTTPMethod = "POST"
    request.addValue("application/json", forHTTPHeaderField: "Content-Type")
    request.addValue("application/json", forHTTPHeaderField: "Accept")


   var task = self.mainSession.downloadTaskWithRequest(request)

    task.resume()
}

func setArray() {
    var result: NSMutableArray = ["bob"]

    result = ["billy", "bob"]
    self.mutableArray = result
}

func callArray()     {

    setArray()
}