Call function from other ViewController

Question

I have two ViewControllers, FirstViewController and SecondViewController. Both have an own Swift file, FirstViewController.swift and

Answer 1

EDIT: These functions have been revised in swift 3 as follows:

Code in FirstViewController

 override function viewDidLoad(){
NotificationCenter.default.addObserver(self, selector: #selector(showAlert), name: NSNotification.Name(rawValue: "showAlert"), object: nil)
}

Code in SecondViewController:

@IBAction func callFunctionInOtherClass(sender: AnyObject) {
 NotificationCenter.default.post(name: NSNotification.Name(rawValue: "showAlert"), object: nil)
}