Fatal error: Index out of range when filling cells - swift

Question

I am getting the this error: Index out of range when trying to fill cells out of a table, any idea why this happens?
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell: VCInstanciasCell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath) as! VCInstanciasCell
cell.siteLabel.text = String?([arrayItinerario[indexPath.section]][indexPath.row].ubicacion!) ?? ""
cell.txtLabel.text = String?([arrayItinerario[indexPath.section]][indexPath.row].maquinaTipo!) ?? ""
cell.orderLabel.text = String?([arrayItinerario[indexPath.section]][indexPath.row].fma!) ?? ""
cell.codeLabel.text = String?([arrayItinerario[indexPath.section]][indexPath.row].iso!) ?? ""
cell.newLabel.text = String?([arrayItinerario[indexPath.section]][indexPath.row].instanciaID!) ?? ""
cell.setLeftUtilityButtons(self.leftButtons(), withButtonWidth: 50.0)
return cell
}
the error is at cell.siteLabel.text = String?([arrayItinerario[indexPath.section]][indexPath.row].ubicacion!) ?? "" in indexPath.Row

Answer 1

It is quite hard to answer this question without seeing how arrayItinerario is defined, and what triggers the cellForRow (when is the timing you're calling reloadData)
But first of all, I'd try to simplify your code, it will make it easier to understand where the crash comes from, as you're using force unwrapped and also cannot know in which of the row/section you get the index out of range.
I added some checks + guards + prints, it will explain my answer + make your testing easier:
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell: VCInstanciasCell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath) as! VCInstanciasCell
if let value = value(for: indexPath) {
cell.siteLabel.text = ""
if let ubicacion = value.ubicacion {
cell.siteLabel.text = String(ubicacion)
}
// and so on
} else {
print("couldn't get value for indexPath:\(indexPath)")
}
return cell
}
func value(for indexPath: IndexPath) -> SomeObject? {
let section = indexPath.section
let row = indexPath.row
guard section < arrayItinerario.count else {
print("section \(section) is out of range for list with count: \(arrayItinerario.count)")
return nil
}
let list = arrayItinerario[section]
guard row < list.count else {
print("row \(row) is out of range for list with count: \(list.count)")
return nil
}
return list[row]
}