I get an error on the Swift user login screen - swift

Question

I've added screenshots below. I'm delighted to see you. Thank you
user login Screen
Error
override func viewDidLoad() {
super.viewDidLoad()
let tap: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: "dismissKeyboard")
view.addGestureRecognizer(tap)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#IBAction func btnGirisYap(_ sender: Any) {
var pass : String!
I assign txtGirisSifre.text as variable "pass"
let arayüzPass = txtGirisSifre.text
var request = URLRequest(url: URL(string: "http://242.253.114.125:7001/WebApplicationo2/login")!)
request.httpMethod = "POST"
let postString = "user=emrekacan"
request.httpBody = postString.data(using: .utf8)
let task = URLSession.shared.dataTask(with: request) { data, response, error in
if error != nil
{
}
else
{
if let urlContent = data
{
do
{
let jsonResult = try JSONSerialization.jsonObject(with: urlContent, options: JSONSerialization.ReadingOptions.mutableContainers) as AnyObject
if let currencyRate = jsonResult as? NSArray
{
for i in 0..<currencyRate.count
{
if let gelenPass = (currencyRate[i] as? NSDictionary)?["pass"] as? String
{
pass = gelenPass
print(pass)
print(arayüzPass!)
}
}
If the password that is called web service is not empty in this section
if pass != nil {
self.login(pass1: pass , arayüzPass1: arayüzPass!)
}
}
}
catch
{
}
}
}
}
task.resume()
}
func dismissKeyboard() {
//Causes the view (or one of its embedded text fields) to resign the first responder status.
view.endEditing(true)
}
func textFieldShouldReturn(_ textField: UITextField) -> Bool {
textField.resignFirstResponder()
return true
}
It gives an error after this section
func login(pass1 : String , arayüzPass1 : String!)
{
"SWRevealViewController" storyboard open
if pass1 == arayüzPass1 {
let storyBoard : UIStoryboard = UIStoryboard(name: "Main", bundle:nil)
let resultViewController = storyBoard.instantiateViewController(withIdentifier: "RevealView") as! SWRevealViewController
self.present(resultViewController, animated:true, completion:nil)
}
}
}