My cells are duplicating themselves - swift

Question

I am new to swift and I am trying to make this note app. I have split view controller that goes in my first view controller and that view controller connects to a table view controller. Everything works perfectly is just that when I launch the app I have all the notes like I want but when I try to go back to my first view controller and come back to my table view controller, all the notes are duplicated every single time I do it. I tried everything I can try, is there anyone who can help me
my MasterViewController is
import UIKit
class MasterViewController: UITableViewController {
var detailViewController: DetailViewController? = nil
override func viewDidLoad()
{
super.viewDidLoad()
Note.loadNotes() // The problem is here, I think
noteTable = self.tableView
// Do any additional setup after loading the view, typically from a nib.
let addButton = UIBarButtonItem(barButtonSystemItem: .add, target: self, action: #selector(insertNewObject(_:)))
navigationItem.rightBarButtonItem = addButton
if let split = splitViewController
{
let controllers = split.viewControllers
detailViewController = (controllers[controllers.count-1] as! UINavigationController).topViewController as? DetailViewController
}
}
My loadNotes function is
class func loadNotes()
{
let defaults:UserDefaults = UserDefaults.standard
let saveData: [NSDictionary]? = defaults.object(forKey: kAllNotes) as? [NSDictionary]
if let data:[NSDictionary] = saveData
{
for i:Int in 0 ..< data.count
{
let n:Note = Note()
n.setValuesForKeys(data[i] as! [String : Any])
allNotes.append(n)
}
}
}

Answer 1

Your loadNotes method keeps appending. The first line of loadNotes should be:
allNotes = [Note]()
Then it starts with an empty array and fills it up.
And why is loadNotes a static method? That's a bad design. Make Notes a normal class and make loadNotes an instance method.
On an unrelated note (no pun intended), do not use UserDefaults to store app data. Only use it to store little bits of information.