Table View UI error: Swift - swift

Question

On the last question I asked about the code error in my animal table view project, now I finished the initial coding, but my UI turned really strange. It is missing the first letter of each animal name and the table view prototype cell.
For example, amel should be camel and hinoceros should be rhinoceros.
Is this a bug from the code here?
import UIKit
class AnimalTableViewController: UITableViewController {
var animalsDict = [String: [String]] ()
var animalSelectionTitles = [String] ()
let animals = ["Bear", "Black Swan", "Buffalo", "Camel", "Cockatoo", "Dog", "Donkey", "Emu", "Giraffe", "Greater Rhea", "Hippopotamus", "Horse", "Koala", "Lion", "Llama", "Manatus", "Meerkat", "Panda", "Peacock", "Pig", "Platypus", "Polar Bear", "Rhinoceros", "Seagull", "Tasmania Devil", "Whale", "Whale Shark", "Wombat"]
func createAnimalDict() {
for animal in animals {
let animalKey = animal.substringFromIndex(advance(animal.startIndex, 1))
if var animalValues = animalsDict[animalKey] {
animalValues.append(animal)
animalsDict[animalKey] = animalValues
} else {
animalsDict[animalKey] = [animal]
}
}
animalSelectionTitles = [String] (animalsDict.keys)
animalSelectionTitles.sort({ $0 < $1})
animalSelectionTitles.sort( { (s1:String, s2:String) -> Bool in
return s1 < s2
})
}
override func viewDidLoad() {
super.viewDidLoad()
createAnimalDict()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
// MARK: - Table view data source
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
// Return the number of sections.
return animalSelectionTitles.count
}
override func tableView(tableView: UITableView, titleForHeaderInSection section:Int) -> String? {
// Return the number of rows in the section.
return animalSelectionTitles[section]
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as! UITableViewCell
let animalKey = animalSelectionTitles[indexPath.section]
if let animalValues = animalsDict[animalKey] {
cell.textLabel?.text = animalValues[indexPath.row]
let imageFileName = animalValues[indexPath.row].lowercaseString.stringByReplacingOccurrencesOfString("", withString: "_", options: nil, range: nil)
cell.imageView?.image = UIImage(named:imageFileName)
}
return cell
}
}

Answer 1

So far I can say the error is in your createAnimalDict() method. In the line
let animalKey = animal.substringFromIndex(advance(animal.startIndex, 1))
exchange the second parameter in advance to 0 so it be:
let animalKey = animal.substringFromIndex(advance(animal.startIndex, 0))
In fact I don't really know what you are trying to do.

Answer 2

In this method:
override func tableView(tableView: UITableView, titleForHeaderInSection section:Int) -> String? {
// Return the number of rows in the section. (THIS COMMENT IS INCORRECT)
return animalSelectionTitles[section]
}
You are returning the title for each section. However your animalSelectionTitles[index] contains the animal name without the first letter due to its construction in createAnimalDict
Use the animal array instead for providing the full animal names:
override func tableView(tableView: UITableView, titleForHeaderInSection section:Int) -> String? {
return animals[section]
}
However note that due to the removal of the first letter you might have two animals mapping to the same key so if not necessary use the entire animal name as the key.