didSelectRowAtIndexPath performSegueWithIdentifier = i get nil in target view - ios

Question

i have ThirdView in my "start" view
import Foundation
import UIKit
class ThirdView : UITableViewController {
var jsonz:NSArray = ["Ray Wenderlich"];
var valueToPass : String?;
var programVar : String?;
override func viewDidLoad() {
super.viewDidLoad()
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject!) {
var newProgramVar = "lol";
let destinationVC = segue.destinationViewController as! FourthView
destinationVC.programVar = newProgramVar
}
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1;
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return self.jsonz.count;
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let myCell = self.tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as! UITableViewCell
myCell.textLabel?.text = self.jsonz[indexPath.row] as? String;
return myCell;
}
override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
let valueToPass = "asd";
let destinationVC = FourthView()
destinationVC.valuePassed = valueToPass;
self.performSegueWithIdentifier("restDetail", sender: tableView);
}
}
I have a segue identifier: restDetail
When i run a project and click on cell, i cant recieve a variable valuePassed in "second" view, i get nil. Please help, why?
But i normal recieve a variable programVar from function prepareForSegue, it is ok. I have only problem with didSelectRowAtIndexPath segue.
It is my FourthView:
import UIKit
class FourthView: UIViewController {
var valuePassed:String!
var programVar:String!
override func viewDidLoad() {
super.viewDidLoad()
println(valuePassed);
println(programVar);
// Do any additional setup after loading the view.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
See here what i have in output:
nil
lol
nil
lol
And second question: why in output it shows 4 times?
Sorry for my english.

Answer 1

In didSelectRowAtIndexPath you are not initializing the FourthView instance correctly.
This line:
let destinationVC = FourthView()
Creates a random instance of FourthView, that isn't the one you're using as destination.
If you want to pass a value to the FourthView it's usually best to do that in prepareForSegue.
As you can see in the line below, here you are setting the destinationVC variable to FourthView instance, which is the destination View Controller of your segue.
let destinationVC = segue.destinationViewController as! FourthView

Answer 2

The issue is with the following code:
let valueToPass = "asd";
let destinationVC = FourthView()
destinationVC.valuePassed = valueToPass;
You are allocating a temporary instance of FourthView and passing data to it. And after that you perform a segue. Perform segue initialises your view controller and loads it to the view (different one, not the one you initialised manually in the didSelectRowAtIndexPath). You need to pass the data from the prepareForSegue: method.