Question

我正在尝试为教程制作一个简单的彩票应用程序，有5个主球图像将显示1-50中的任何数字，还有两个星球图像将显示1-9中的任何数字，但由于某些原因，我收到错误致命错误：索引超出范围。谁能从下面的代码中看到为什么我会收到此错误？我正在XCode 10.1中进行编码，并使用swift作为语言。预先感谢

import UIKit

class ViewController: UIViewController {
    let ballArray = ["poolball1","poolball2","poolball3","poolball4","poolball5","poolball6","poolball7","poolball8","poolball9","poolball10","poolball11","poolball12","poolball13","poolball14","poolball15","poolball16","poolball17","poolball18","poolball19","poolball20","poolball21","poolball22","poolball23","poolball24","poolball25","poolball26","poolball27","poolball28","poolball29","poolball30","poolball31","poolball32","poolball33","poolball34","poolball35","poolball36","poolball37","poolball38","poolball39","poolball40","poolball41","poolball42","poolball43","poolball44","poolball45","poolball46","poolball47","poolball48","poolball49","poolball50"]
    let luckyBallArray = ["poolballLS1", "poolballLS2", "poolballLS3", "poolballLS4", "poolballLS5", "poolballLS6", "poolballLS7", "poolballLS8", "poolballLS9"]

    var randomPoolBallIndex: Int = 0
    var randomPoolBallIndex1: Int = 0
    var randomPoolBallIndex2: Int = 0
    var randomPoolBallIndex3: Int = 0
    var randomPoolBallIndex4: Int = 0
    var randomPoolBallIndex5: Int = 0

    var randomPoolBallLuckyIndex: Int = 0
    var randomPoolBallLuckyIndex1: Int = 0
    var randomPoolBallLuckyIndex2: Int = 0

    @IBOutlet weak var poolBallView1: UIImageView!
    @IBOutlet weak var poolBallView2: UIImageView!
    @IBOutlet weak var poolBallView3: UIImageView!
    @IBOutlet weak var poolBallView4: UIImageView!
    @IBOutlet weak var poolBallView5: UIImageView!

    @IBOutlet weak var poolLuckyView1: UIImageView!
    @IBOutlet weak var poolLuckyView2: UIImageView!

    @IBAction func buttonPressed(_ sender: UIButton) {
        randomPoolBallIndex1 = Int.random(in: 0 ... 50)
        randomPoolBallIndex2 = Int.random(in: 0 ... 50)
        randomPoolBallIndex3 = Int.random(in: 0 ... 50)
        randomPoolBallIndex4 = Int.random(in: 0 ... 50)
        randomPoolBallIndex5 = Int.random(in: 0 ... 50)

        randomPoolBallLuckyIndex1 = Int.random(in: 0 ... 9)
        randomPoolBallLuckyIndex2 = Int.random(in: 0 ... 9)

        poolBallView1.image = UIImage(named: ballArray[randomPoolBallIndex1])
        poolBallView2.image = UIImage(named: ballArray[randomPoolBallIndex2])
        poolBallView3.image = UIImage(named: ballArray[randomPoolBallIndex3])
        poolBallView4.image = UIImage(named: ballArray[randomPoolBallIndex4])
        poolBallView5.image = UIImage(named: ballArray[randomPoolBallIndex5])

        poolLuckyView1.image = UIImage(named: luckyBallArray[randomPoolBallLuckyIndex1])
        poolLuckyView2.image = UIImage(named: luckyBallArray[randomPoolBallLuckyIndex2])
    }
}

Answer 1

根据您的问题，您有ballArray和1 to 50的球。但是，您应该知道，数组从索引0开始。这意味着，如果元素数为50，则索引范围为0 to 49。

这是您尝试过的：

randomPoolBallIndex1 = Int.random(in: 0...50)
poolBallView1.image = UIImage(named: ballArray[randomPoolBallIndex1])

您正在尝试从索引0 to 50中获得一个随机球。但是，您正在尝试访问0 to 49范围之外的元素，这意味着您将当机。

您还需要修复此代码的多个副本。

您需要做的就是更改以下行：

randomPoolBallIndex1 = Int.random(in: 0...50)

更像这样：

randomPoolBallIndex1 = Int.random(in: 0...49) // Closed range
randomPoolBallIndex1 = Int.random(in: 0..<50) // Half-open range

详细了解Ranges，例如Closed Range (...)和Half-open Range (..<)。

Answer 2

球阵列中只有49个元素，而幸运球阵列中只有8个元素。

因此，您需要执行0 ... 49和0 ... 8。

我不断获取：致命错误：索引超出范围

2 个答案: