Swift Xcode 6棒球计数器

我不能写出如果陈述到底是为了让罢工达到3时出局？ 有人可以帮助他们，并迅速做出这样的事情

// // ViewController.swift // helloWordDemo // // Created by Developer on 6/8/14. // Copyright (c) 2014 AECApps. All rights reserved. // import UIKit class ViewController: UIViewController { 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. } @IBOutlet var labelDispaly : UILabel = nil // dispaly Strikes var counter = 1 @IBAction func buttonPressed(sender : AnyObject) { labelDispaly.text = "Strikes \(counter++)" } //button to add strikes @IBOutlet var OutsDispaly : UILabel = nil var outsCounter = 1 //outs dispaly @IBAction func outsButtonPressed(sender : AnyObject) { OutsDispaly.text = "Outs \(outsCounter++)" } //button to add outs if counter = 3 { outsCounter ++ } } 

Answer 1

使用属性观察者：

 var counter = 1 { didSet { if counter == 3 { self.outsCounter++ } } } 

每当counter被改变时，didSet都会被调用。

（还要注意的是，等号运算符是== 。 =用于赋值。）