计数对象数组中的错误

traff 发表于 Dev

打

我有这个代码：

var activeCalculators = Calculators()

func numberOfCalculators()->Int{
        let activeCalculatorsArray = activeCalculators.calculators
        return activeCalculatorsArray!.count
    }


struct Calculators
{
    var calculators: [Calculator]?
    var activeCalculator: Int = -1
    var activeSummary: Bool = false
    var activeProfits: Bool = false

    public func getCalculators()-> [Calculator]
    {
        return calculators!
    }

    public mutating func setCalculators(calculators: [Calculator])
    {
        self.calculators = calculators
    }

    public func  getActiveCalculatorIndex()-> Int
    {
        return activeCalculator
    }

    public mutating func  setActiveCalculatorIndex( activeCalculator: Int)
    {
        self.activeCalculator = activeCalculator
    }

    public func  isActiveProfits()-> Bool
    {
        return activeProfits
    }

    public mutating func  setActiveProfits( activeProfits: Bool)
    {
        self.activeProfits = activeProfits
    }



    public func  isActiveSummary()-> Bool
    {
        return activeSummary
    }

    public mutating func setActiveSummary(activeSummary: Bool)
    {
        self.activeSummary = activeSummary
    }
}

override func viewDidLoad() {
print("XXXXXXXXXXXX: \(numberOfCalculators())")

}

当我运行我的函数时：numberOfCalculators() 我有错误：线程 1：致命错误：在解开可选值时意外发现 nil

我正在尝试将此功能添加到我的课程中：

public func countCalculators()->Int{
        return (calculators?.count)!
    }

但他们我有错误：

线程 1：EXC_BAD_INSTRUCTION（代码=EXC_I386_INVOP，子代码=0x0）

你怎么能修好呢？

沙拉德·乔汉

首先，正确打开它：

func numberOfCalculators()->Int{
    return activeCalculatorsArray?.count ?? 0
}

public func countCalculators()->Int {
    return calculators?.count ?? 0 // Suggested by Alexander
}

那么你需要set something before calling get。因此，viewDidLoad不要先调用numberOfCalculators()call，setCalculators()这样您就可以为计算器提供一些价值。

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