use a switch to change the value of boolean saved core data value - swift

Question

In my swift code below right now the code saves 2 boolean values to a core data boolean value. The two values are true false. I would like the user to turn on the switch and have the 2nd value be true as well. So it would be true true. I am trying to do that in func alternate() but I dont know how to exactly effect a specific value. Looking for any kind of help.
import UIKit;import CoreData
class ViewController: UIViewController {
var lbl = UILabel()
var sw = UISwitch()
var checkmarkButton = UIButton()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
[ lbl,sw,checkmarkButton].forEach {
view.addSubview($0)
$0.translatesAutoresizingMaskIntoConstraints = false
$0.layer.borderWidth = 1
}
helpBool.shareInstance.saveBoolean(true)
helpBool.shareInstance.saveBoolean(false)
getBool(imageNo: 1)
}
func getBool(imageNo:Int) {
// first check the array bounds
let info = helpBool.shareInstance.fetchBool()
if info.count > imageNo {
// if info[imageNo].bool {
if info[imageNo].bool == true {
checkmarkButton.setImage(UIImage(named:"unnamed"), for: .normal);
}
if info[imageNo].bool == false {
checkmarkButton.setImage(nil, for: .normal);
}
// }
}
}
#objc func alternate(){
//fetch alternate
getBool(imageNo: 1)
if sw.isOn = true {
helpBool.shareInstance.saveBoolean()
}
else {
helpBool.shareInstance.saveBoolean()
}
}
}
class helpBool: UIViewController{
static let shareInstance = helpBool()
let context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
func saveBoolean(_ boolean: Bool) {
let imageInstance = OnOff(context: context)
imageInstance.bool = boolean
do {
try context.save()
print("text is saved")
} catch {
print(error.localizedDescription)
}
}
func fetchBool() -> [OnOff] {
var fetchingImage = [OnOff]()
let fetchRequest = NSFetchRequest<NSFetchRequestResult>(entityName: "OnOff")
do {
fetchingImage = try context.fetch(fetchRequest) as! [OnOff]
} catch {
print("Error while fetching the image")
}
return fetchingImage
}
}