Connecting Two UISegmentedControllers - ios

Question

I have been having trouble synchronizing the values of two UISegments. The First UISegment is suppose to get updated based on the value of the second UISegment (which is in a different ViewController) and then update the value in its own segment based on what is selected in the second ViewController. However, the values are not transferring to the first UISegment, meaning the title and value is not being stored even though I am using the defaults and storing keys.
ViewController
import UIKit
class ViewController: UIViewController {
#IBOutlet weak var tipLabel: UILabel!
#IBOutlet weak var totalLabel: UILabel!
#IBOutlet weak var billField: UITextField!
#IBOutlet weak var tipController: UISegmentedControl!
#IBOutlet weak var splitController: UISegmentedControl!
#IBOutlet weak var splitLabel: UILabel!
let defaults = UserDefaults.standard
override func viewDidLoad() {
super.viewDidLoad()
defaults.synchronize()
billField.becomeFirstResponder()
billField.text = String(defaults.double(forKey: "bill_value"))
print(tipController.selectedSegmentIndex)
if billField.text == "" || (billField.text == nil) {
billField.placeholder = String(0.00)
}
billField.becomeFirstResponder()
tipController.selectedSegmentIndex = defaults.integer(forKey: "default_tip_index")
}
override func viewWillAppear(_ animated: Bool) {
tipController.selectedSegmentIndex = defaults.integer(forKey: "default_tip_index")
}
#IBAction func onTap(_ sender: Any) {
view.endEditing(true)
}
#IBAction func calculateTip(_ sender: Any) {
let tipPercentages = [0.18, 0.20, 0.25]
let splitNumbers = [1,2,3,4]
let bill = Double(billField.text!) ?? 0 //converts bill to double
defaults.set(bill, forKey: "bill_value") //Saves last bill input
let tip = bill * tipPercentages[tipController.selectedSegmentIndex]
let total = bill + tip
tipLabel.text = String(format: "$%.2f", tip)
totalLabel.text = String(format: "$%.2f", total)
splitLabel.text = String(format: "$%.2f", total/Double((splitNumbers[splitController.selectedSegmentIndex])))
}
}
SettingsViewController
class SettingsViewController: UIViewController {
var tipPercentageIndex:Int!
#IBOutlet weak var settingsTipController: UISegmentedControl!
let defaults = UserDefaults.standard
override func viewDidLoad() {
super.viewDidLoad()
let selectedDefaultPercent = defaults.integer(forKey: "default_tip_index")
settingsTipController.selectedSegmentIndex = selectedDefaultPercent
}
#IBAction func tipPercent(_ sender: Any) {
defaults.set(settingsTipController.selectedSegmentIndex, forKey: "default_tip_index")
defaults.synchronize()
}
#IBAction func splitNumber(_ sender: Any) {
}
#IBAction func Back(_ sender: Any) {
self.performSegue(withIdentifier: "Tippy2", sender: self)
}
}
Overall this simple application calculates the tip and updates the first UISegment when the settingsViewController is visited.