Why am I not able to access global variables? - ios

Question

I am new both to coding and to Xcode and am working on my first iOS app - so please forgive me if the answer to my question is obvious to experienced developers.
My app works but the design looks very "old fashioned" due to the buttons I have on each View Controller. I would prefer to use a more modern navigation system using Navigation Bars with Navigation buttons at the top of each screen. However, when I use this method of navigation the global variables entered on my first View Controller cannot be accessed on my final View Controller. I have double checked my Swift code files for each View Controller which, as explained, works fine if I have UIButtons instead of the Navbar.
The only difference I can see is that the Xcode 11 Navbar system uses the "Show" (Push) method of segues between View Controllers whereas my storyboard buttons use modal presentation.
I would be grateful if someone can steer me in the right direction - thanks!
The code showing the global variables from the first view controller is:
\\
import UIKit
var name = ""
var lastname = ""
var address = ""
var city = ""
var zip = ""
var email = ""
var phone = ""
var dateofbirth = ""
class ViewController1: UIViewController {
#IBOutlet weak var outlet: UITextField!
#IBOutlet weak var outlet2: UITextField!
#IBOutlet weak var outlet6: UITextField!
#IBOutlet weak var outlet3: UITextField!
#IBOutlet weak var outlet4: UITextField!
#IBOutlet weak var outlet5: UITextField!
#IBOutlet weak var outlet8: UITextField!
#IBOutlet weak var outlet7: UITextField!
#IBAction func submit(_ sender: Any) {
// Code for First Name
if (outlet.text != "")
{
name = outlet.text!
}
// Code for Last Name
if (outlet2.text != "")
{
lastname = outlet2.text!
}
// Code for Address
if (outlet3.text != "")
{
address = outlet3.text!
}
// Code for city
if (outlet4.text != "")
{
city = outlet4.text!
}
// Code for Zip
if (outlet5.text != "")
{
zip = outlet5.text!
}
// Code for Email
if (outlet6.text != "")
{
email = outlet6.text!
}
// Code for Phone
if (outlet7.text != "")
{
phone = outlet7.text!
}
// Code for Date of Birth
if (outlet8.text != "")
{
dateofbirth = outlet8.text!
}
// Dismissal of Keyboard
}
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
view.endEditing(true)
super.touchesBegan(touches, with: event)
}
override func viewDidLoad() {
super.viewDidLoad()
}
}
\\\\
The code for the final View Controller is:
\\\\
import UIKit
class ReportViewController: UIViewController {
//Client ID Label Outlets
#IBOutlet weak var Label: UILabel!
#IBOutlet weak var Label2: UILabel!
#IBOutlet weak var Label3: UILabel!
#IBOutlet weak var Label4: UILabel!
#IBOutlet weak var Label5: UILabel!
#IBOutlet weak var Label6: UILabel!
#IBOutlet weak var Label7: UILabel!
#IBOutlet weak var Label8: UILabel!
// Return function
#IBAction func unwindToReportVC (_sender:UIStoryboardSegue){
}
override func viewDidLoad() {
super.viewDidLoad()
}
override func viewDidAppear(_ animated:Bool){
// Client ID Labels text using declared global variables
Label.text = name
Label2.text = lastname
Label3.text = address
Label4.text = city
Label5.text = zip
Label6.text = email
Label7.text = phone
Label8.text = dateofbirth
}
}