How can I make a swift multiple questions quiz so the questions do not repeat themselves?

I do not have any experience with programing. I have done this looking at youtube videos for a couple of months. I will really appreciate if someone can please help me. When I run the code with the simulator it repeats the questions several time before the next new question is presented. I would like it to run so it presents one question without repeating the same question over and over. Below please find the code. import UIKit class ViewController: UIViewController { @IBOutlet weak var QuestionLabel: UILabel! @IBOutlet weak var Button1: UIButton! @IBOutlet weak var Button2: UIButton! @IBOutlet weak var Button3: UIButton! @IBOutlet weak var Button4: UIButton! @IBOutlet weak var Next: UIButton! @IBOutlet weak var LabelEnd: UILabel! var CorrectAnswer = String() override func viewDidLoad() { super.viewDidLoad() // Do any additional setup after loading the view, typically from a nib. Hide() RamdomQuestions() } func RamdomQuestions () { var RandomNumber = arc4random() % 4 RandomNumber += 1 switch (RandomNumber) { case 1: QuestionLabel.text = "Hola familia, Cual es mi nombre? " Button1.setTitle ("Cesar", forState: UIControlState.Normal) Button2.setTitle ("Karlos", forState: UIControlState.Normal) Button3.setTitle ("William", forState: UIControlState.Normal) Button4.setTitle ("Chiqui", forState: UIControlState.Normal) CorrectAnswer = "2" break case 2: QuestionLabel.text = "Hola famili, cual es mi apellido? " Button1.setTitle ("Perez", forState: UIControlState.Normal) Button2.setTitle ("Carvajal", forState: UIControlState.Normal) Button3.setTitle ("Garcia", forState: UIControlState.Normal) Button4.setTitle ("Sanchez", forState: UIControlState.Normal) CorrectAnswer = "1" break case 3: QuestionLabel.text = "Quien hace la lachona mas rica? " Button1.setTitle ("Willy", forState: UIControlState.Normal) Button2.setTitle ("Mario", forState: UIControlState.Normal) Button3.setTitle ("Karlos", forState: UIControlState.Normal) Button4.setTitle ("Juan David", forState: UIControlState.Normal) CorrectAnswer = "1" break case 4: QuestionLabel.text = "Quien hace las tartas mas lindas" Button1.setTitle ("Jili", forState: UIControlState.Normal) Button2.setTitle ("Carvajal", forState: UIControlState.Normal) Button3.setTitle ("Garcia", forState: UIControlState.Normal) Button4.setTitle ("Leidy y Liz", forState: UIControlState.Normal) CorrectAnswer = "4" break default: break } } func Hide (){ LabelEnd.hidden = true Next.hidden = true } func UnHide () { LabelEnd.hidden = false Next.hidden = false } @IBAction func Button1Action(sender: AnyObject) { UnHide() if (CorrectAnswer == "1") { LabelEnd.text = "Correcto" } else{ LabelEnd.text = "Falso" } } func Button2Action(sender: AnyObject) { UnHide() if (CorrectAnswer == "2") { LabelEnd.text = "Correcto" } else{ LabelEnd.text = "Falso" } } func Button3Action(sender: AnyObject) { UnHide() if (CorrectAnswer == "3") { LabelEnd.text = "Correcto" } else{ LabelEnd.text = "Falso" } } func Button4Action(sender: AnyObject) { UnHide() if (CorrectAnswer == "4") { LabelEnd.text = "Correcto" } else{ LabelEnd.text = "Falso" } } @IBAction func Next(sender: AnyObject) { RamdomQuestions() } }