ios - Pass one variable from one viewcontroller to another viewcontroller

Question

I new to swift language and know this question is duplicated.I`ve found several similar question and answer, but i could not able to figure out the problem.

I want to pass the value of detectionString variable to ResultViewController from ScanViewController.

ScanViewcontroller as below:

import UIkit

class ScanViewController: UIViewController  {

    var detectionString : String!

    override func viewDidLoad() {
        super.viewDidLoad()

        detectionString = “SomeDetectedString”
    }

    override func prepareForSegue(segue: UIStoryboardSegue,sender: AnyObject!) {
        if (segue.identifier == "MySegue") {
            var svc = segue.destinationViewController as ResultViewController;
            svc.detectedString = detectionString
        }
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }
}

The ResultViewController as below:

import UIkit

class ResultViewController: UIViewController {

    var detectedString: String!

    override func viewDidLoad() {
        super.viewDidLoad()
        self.view.backgroundColor=UIColor.whiteColor()
        println(detectedString)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }
}

The println(detectedString) gives me no result. question is that how can get the variable from ScanViewController?

Answer 1

your segue.identifier == "MySegue" is some how not comparing in the way it should.

replace your code with following function and you are done.

override func prepareForSegue(segue: UIStoryboardSegue,sender: AnyObject!) {
    let segueName: String = segue.identifier!;
    if (segueName == "MySegue") {
        var svc = segue.destinationViewController as DetailVC;
        svc.detectedString = detectionString
    }
}