Load data from JSON file to a table - ios

Question

I have a Core Data model called 'List' with 4 attributes and wanted to populate the data from the JSON file to an array of type 'List'
when I run the app, it gives me the error 'fatal error: Array index out of range'
var loadNames = [List]()
var context = (UIApplication.sharedApplication().delegate as! AppDelegate).managedObjectContext!
var frc: NSFetchedResultsController = NSFetchedResultsController()
func getFetchedResultsController() -> NSFetchedResultsController {
frc = NSFetchedResultsController(
fetchRequest: listFetchRequest(),
managedObjectContext: context,
sectionNameKeyPath: "done",
cacheName: nil)
return frc
}
func listFetchRequest() -> NSFetchRequest {
let fetchRequest = NSFetchRequest(entityName: "List")
let doneSortDescriptor = NSSortDescriptor(key: "done", ascending: false)
let nameSortDescriptor = NSSortDescriptor(key: "firstName", ascending: true)
fetchRequest.sortDescriptors = [doneSortDescriptor, nameSortDescriptor]
return fetchRequest
}
func isFrequent(item: List) -> Bool {
return item.frequent == true
}
override func viewWillAppear(animated: Bool) {
var readError:NSError?
let filePath = NSBundle.mainBundle().pathForResource("NameList", ofType:"json")
let data = NSData(contentsOfFile:filePath!, options: NSDataReadingOptions.DataReadingUncached, error:&readError)
var jData = NSJSONSerialization.JSONObjectWithData(data!, options: .MutableContainers, error: &readError) as! NSArray
for i in 0..<jData.count {
if let jfName = jData[i]["firstName"] as? String {
if let jlName = jData[i]["lastName"] as? String {
if let jDone = jData[i]["done"] as? NSNumber {
if let jFrequent = jData[i]["frequent"] as? NSNumber {
loadNames[i].firstName = jfName //This is where the error is pointing.
loadNames[i].lastName = jlName
loadNames[i].done = jDone
loadNames[i].frequent = jFrequent
println(loadNames.count)
}
}
}
}
}
}
the variables all seem to be getting the data from the JSON file and the value of 'i' in the 'for' loop when the error is happening is '0'.
I don't know why this is happening.
the array count is returning 6, which is the actual amount of objects in the JSON file.

Answer 1

You should use the loadNames array's append method to add each List object. Trying to access index i >= 0 in a zero length array is what is causing your error.