How to save selected option in UIPickerView

I have a PickerView which should save the selected pickerView but it is selecting only the default option.I have tried using user default but it didn't work.

I am using Xcode 8.

    func numberOfComponents(in pickerView: UIPickerView) -> Int {        return 1    }    func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {        return pizzaToppings.count    }    func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {        pizzaTextField.text = pizzaToppings[row]        UserDefaults.standard.set(row, forKey: "pickerViewRow")    }   func pickerView(_ pickerView: UIPickerView, attributedTitleForRow row: Int, forComponent component: Int) -> NSAttributedString? {    let attrb = NSAttributedString(string: pizzaToppings[row])        return attrb    }    func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {        return pizzaToppings[row]    }

And In overload function I have used user default

 override func viewDidLoad() {    let row = UserDefaults.standard.integer(forKey: "pickerViewRow")    pickerView.selectRow(row, inComponent: 0, animated: false)