IOS tableview issue - ios

Question

I'm having an issue where my app will freeze if when I press it to got the next scene which is a view controller with a tableview nested inside of it. the app will only freeze when I've declared how many rows the table will have. If anyone knows how to fix this problem its be greatly appreciated.
class ViewController: UIViewController, UITableViewDataSource {
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 5
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
var cell = UITableViewCell()
cell.textLabel?.text = "hello"
return cell
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}

Answer 1

Have you set dataSource of your table view? You must call tableView.dataSource = self somewhere in your code (most probably in viewDidLoad method)

Answer 2

The problem with your code is that in tableView(_:cellForRowAtIndexPath:) you are creating new cell every time the method is called. That is not how table views (or collection views) work.
The idea behind these components is to reuse their cells so that your application shows better performance. What if you have 1000 cells? You will create 1000 UITableViewCell objects for each cell? This is where dequeueReusableCellWithIdentifier(_:) comes in handy.
So set an identifier for your cell in Interface Builder, for example "Cell" and get the cell like this:
let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as! UITableViewCell
This is the right way to go.

Answer 3

You have to make sure you set the correct reuse identifier for your table view cell (either in storyboard, or code).
Storyboard:
Of if you want to do it in code, put this in viewDidLoad():
tableView.registerClass(UITableViewCell, forHeaderFooterViewReuseIdentifier: "cellIdentifier")
Important to know that you should only use one of the above. If you define your UI in Storyboards, I recommend the first approach.
Then when you create the cell in tableView(_:, cellForRowAtIndexPath), instead of this:
var cell = UITableViewCell()
Use a cell from the reuse queue like so:
var cell = tableView.dequeueReusableCellWithIdentifier("cellIdentifier", forIndexPath: indexPath) as! UITableViewCell

Answer 4

Everytime you are creating object for cell, make sure you use reuse identifier.
let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as! UITableViewCell