Swift 3: index out of range error - ios

Question

I'm new to iOS. Doing project by watching tutorial which is written using Swift 2. It works when author runs app but not in my case.
ViewController:
var books = [[String: AnyObject]]()
override func viewDidLoad() {
super.viewDidLoad()
tableView.dataSource = self
searchBar.delegate = self
}
And the extension
extension ViewController: UITableViewDataSource {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 1
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "BookCell", for: indexPath)
// error on this line
if let volumeInfo = self.books[indexPath.row]["volumeInfo"] as? [String: AnyObject] {
cell.textLabel?.text = volumeInfo["title"] as? String
cell.detailTextLabel?.text = volumeInfo["subtitle"] as? String
}
return cell
}
}
The console output:
Please, help me to identify what is the cause.

Answer 1

You have to return books.count from numberOfRowsInSection, never "hard-code" that value if it's related to the data source array.
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return books.count
}
PS: In Swift 3 you should use [String:Any] rather than [String:AnyObject]

Answer 2

I'm assuming a lot about your project but if you only have one section in your tableView, which is the default, you shouldn't use indexPath.section for your books dictionary. You should use indexPath.row as seen below
Change -
if let volumeInfo = self.books[indexPath.section]["volumeInfo"] as? [String: AnyObject]
To -
if let volumeInfo = self.books[indexPath.row]["volumeInfo"] as? [String: AnyObject] {