title: number of rows contained in existing section after update (15) must equal
body: <p>So i'm building an app as a hobby and have researched, it appears a few people have a similar problem, except mine happens when inserting the data to begin with. So I think it's slightly different. </p>
  
  <p>When I go to insert data into my array and table it returns an error (title), it retrieves the right amount of current count, but struggled to add a new one.</p>
  
  <pre><code>class AccountsViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
      @IBOutlet weak var totalLabel: UILabel!
      @IBOutlet weak var tableview: UITableView!
      @IBOutlet weak var tableview2: UITableView!
  
      override func viewDidLoad() {
          super.viewDidLoad()
  
          //Set the table background as the image
          tableview.backgroundView = UIImageView(image: UIImage(named: "splasnowords-1.png"))
  
          //Use the edit button item provided by the table view controller
          navigationItem.leftBarButtonItem = editButtonItem
          //self.navigationItem.leftBarButtonItem = self.editButtonItem;
  
          //Calculate the latest totalstandings
          BudgetDataModel.calculateTotalStandings()
          totalLabel.text = ("Total Current Standings = £\(BudgetDataModel.returnTrueValue(number: BudgetDataModel.total))")
  
          self.tableview.delegate = self
          self.tableview2.delegate = self
          self.tableview.dataSource = self
          self.tableview2.dataSource = self
      }
  
      // MARK: - Table view data source
      func numberOfSections(in tableView: UITableView) -&gt; Int {
          if (tableView == tableview){
          return 1
              //BudgetDataModel.budgets.count
          }
          else{
              return 2
                  //SavingsDataModel.savings.count
          }
      }
  
      func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -&gt; String?{
          //reload data?
          if (tableView == tableview){
              return "Budgets"
          }
          else{
              return "Savings"
          }
      }
  
      func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -&gt; Int {
          var rowCount = 0
          if (tableView == self.tableview) {
              rowCount = BudgetDataModel.budgets.count
          }
          if (tableView == self.tableview2) {
              rowCount = SavingsDataModel.savings.count
          }
          return rowCount
  
          // #warning Incomplete implementation, return the number of rows
      }
  
      func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -&gt; UITableViewCell {
         //Table view cells are reused and should be dequeued using a cell identifier.
          if (tableView == self.tableview){
              let cellIdentifier = "AccountsTableViewCell"
              let cell = tableView.dequeueReusableCell(withIdentifier: cellIdentifier, for: indexPath) as! AccountsTableViewCell
  
              let budget = BudgetDataModel.budgets[(indexPath as NSIndexPath).row]
  
              cell.nameLabel.text = budget.name
              cell.amountLabel.text = ("£\(BudgetDataModel.returnTrueValue(number: budget.amount))")
              cell.backgroundColor = UIColor(white: 1, alpha: 0.5)
              return cell
          }
          else if (tableView == self.tableview2){
              let cellIdentifier = "SavingsTableViewCell"
              let cell = tableView.dequeueReusableCell(withIdentifier: cellIdentifier, for: indexPath) as! SavingsTableViewCell
              let saving = SavingsDataModel.savings[(indexPath as NSIndexPath).row]
  
              cell.savingsnameLabel.text = saving.savingname
              cell.savingsamountLabel.text = ("£\(BudgetDataModel.returnTrueValue(number: saving.savingamount))")
              cell.backgroundColor = UIColor(white: 1, alpha: 0.5)
              return cell
           }
          else { preconditionFailure ("unexpected cell type") }
      }
  
      // Override to support conditional editing of the table view.
      func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -&gt; Bool {
          // Return false if you do not want the specified item to be editable.
          return true
      }
  
      // Override to support editing the table view.
      func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath) {
          if editingStyle == .delete {
              if (tableView == tableview){
                  // Delete the row from the data source
                  BudgetDataModel.budgets.remove(at: indexPath.row)
                  BudgetDataModel.saveBudgets()
                  BudgetDataModel.calculateTotalStandings()
                  totalLabel.text = ("Total Current Standings = £\(BudgetDataModel.returnTrueValue(number:BudgetDataModel.total))")
                 // self.tableview.reloadData()
                  tableView.deleteRows(at: [indexPath], with: .fade)
  
              }
              else if (tableView == tableview2){
                  // Delete the row from the data source
                  SavingsDataModel.savings.remove(at: indexPath.row)
                  SavingsDataModel.saveSavings()
                  //implement   BudgetDataModel.calculateTotalStandings()
                  //implement   totalLabel.text = ("Total Current Standings = £\(BudgetDataModel.returnTrueValue(number:BudgetDataModel.total))")
                  //self.tableview2.reloadData()
                  tableView.deleteRows(at: [indexPath], with: .fade)
  
              }
          } else if editingStyle == .insert {
              // Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view
          }    
      }
  
      // Override to support rearranging the table view.
      func tableView(_ tableView: UITableView, moveRowAt fromIndexPath: IndexPath, to: IndexPath) {
      }
  
      // MARK: - Navigation
  
      // In a storyboard-based application, you will often want to do a little preparation before navigation
      override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
          if segue.identifier == "ShowDetail"{
              let budgetDetailViewController = segue.destination as! BudgetViewController
              //Get the cell that generated this segue.
              if let selectedBudgetCell = sender as? AccountsTableViewCell {
                  let indexPath = tableview.indexPath(for: selectedBudgetCell)!
                  let selectedBudget = BudgetDataModel.budgets[indexPath.row]
                  budgetDetailViewController.budget = selectedBudget
              }
          }
          else if segue.identifier == "AddItem"{
              //self.tableview.reloadData()
              print("Adding new budget.")
          }
          else if segue.identifier == "ShowSavings"{
                  let savingDetailViewController = segue.destination as! SavingsViewController
                  //Get the cell that generated this segue.
                  if let selectedSavingsCell = sender as? SavingsTableViewCell {
                      let indexPath = tableview2.indexPath(for: selectedSavingsCell)!
                      let selectedSavings = SavingsDataModel.savings[indexPath.row]
                      savingDetailViewController.saving = selectedSavings
                  }
          }
          else if segue.identifier == "AddSaving"{
              //self.tableview2.reloadData()
              print ("Adding new saving.")
          }
      }
  
      //MARK: Actions
  
      @IBAction func unwindToBudgetList(_ sender: UIStoryboardSegue){
          if let sourceViewController = sender.source as? BudgetViewController, let budget = sourceViewController.budget {
              if let selectedIndexPath = tableview.indexPathForSelectedRow{
                  //Update an existing budget.
                  BudgetDataModel.budgets[selectedIndexPath.row] = budget
                  tableview.reloadRows(at: [selectedIndexPath], with: .none)
              }
              else{
                      //Add a new budget
                      let newIndexPath = IndexPath(row:BudgetDataModel.budgets.count, section: 0)
                      BudgetDataModel.budgets.append(budget)
                      tableview.insertRows(at: [newIndexPath as IndexPath], with: .bottom)
                  }
              //Save the budgets.
              BudgetDataModel.saveBudgets()
              BudgetDataModel.calculateTotalStandings()
              totalLabel.text = ("Total Current Standings = £\(BudgetDataModel.returnTrueValue(number: BudgetDataModel.total))")
  
          }
      }
  
      @IBAction func unwindtoSavingsList(_ sender: UIStoryboardSegue){
          if let sourceViewController = sender.source as? SavingsViewController, let savings = sourceViewController.saving {
              if let selectedIndexPath = tableview2.indexPathForSelectedRow{
                  //Update an existing budget.
                  SavingsDataModel.savings[selectedIndexPath.row] = savings
                  tableview2.reloadRows(at: [selectedIndexPath], with: .none)
              }
              else{
                  //Add a new saving
                  let newIndexPath = IndexPath(row:SavingsDataModel.savings.count, section: 1)
                  SavingsDataModel.savings.append(savings)
                  //tableview2.reloadData()
                  tableview2.insertRows(at: [newIndexPath as IndexPath], with: .bottom)
              }
              //Save the budgets.
              SavingsDataModel.saveSavings()
              //implement    SavingsDataModel.calculateTotalStandings()
              //    totalLabel.text = ("Total Current Standings = £\(BudgetDataModel.returnTrueValue(number: BudgetDataModel.total))")
  
          }
      }
  }
  </code></pre>