Question

我搜索过类似的问题，但他们无法解决我的问题，所以我希望没问题，我再问一遍。这是我的代码：

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 weak var revealLabel: UILabel!
@IBOutlet weak var scoreLabel: UILabel!
@IBOutlet weak var textField: UITextField!

var userGuess: Int
var heldUpFingers: Int
var score: Int = 0

@IBAction func startGame(sender: UIButton) {
    userGuess = Int(textField.text!)!
    if textField.text == nil {
        revealLabel.text = "Please enter a number from 1 to 5"
    } else if userGuess > 5 {
        revealLabel.text = "Please enter a number from 1 to 5"
    } else {
        heldUpFingers = Int(arc4random_uniform(5) + 1)
        if heldUpFingers == userGuess {
            revealLabel.text = "You guessed right!"
            score += 1
            scoreLabel.text = String(score)
        } else {
            revealLabel.text = "Wrong, it was \(heldUpFingers)"
        }
    }

}

}

它在第3行给出了错误“Class'ViewController'没有初始值设定项”。提前谢谢！

Answer 1

这是因为userGuess和heldUpFingers尚未分配。您可以通过在?之后添加Int或为其设置默认值来使这些可选。所以：

var userGuess: Int?
var heldUpFingers: Int?

然后你需要打开它们/检查你的代码后面不会这样：

if userGuess != nil {
    //now safely use userGuess!
}

或者

var userGuess: Int = 0
var heldUpFingers: Int = 0

类'ViewController'没有初始值设定项 - 类似问题无法解决问题

1 个答案: