所以我在故事板上有自己生成的饼图,上面有各种标签,滑块,Age,CurrentAsset,Income等按钮。我用struct构建模型,并且我一直在使用&的几种方法出错#34;在预期返回的函数中缺少返回' Double'"即使你可以看到我有currentAssetFactor,savingsFactor,bondFactor,toleranceFactor,outlookFactor的回报。我做错了什么?
public struct AllocationModel
{
let maxAge = 95.0
let currentAge: Double
let minCurrentAsset = 100000.0
let maxCurrentAsset = 500000.0
let currentAsset: Double
let minSavings = 5000.0
let maxSavings = 20000.0
let currentSavings: Double
let maxIncomeRequired = 0.04
let minIncomeRequired = 0.01
let currentIncomeRequired: Double
let tolerance: String
let outlook: String
// MARK: - Methods
public var currentAssetFactor: Double {
if currentAsset > maxCurrentAsset {
return 5.0
} else if currentAsset >= minCurrentAsset {
return Double(currentAsset / minCurrentAsset)
}
}
public var savingsFactor: Double {
if currentSavings >= maxSavings {
return 4.0
} else if currentSavings >= minSavings {
return Double(currentSavings / minSavings)
}
}
public var bondFactor: Double {
if currentIncomeRequired >= maxIncomeRequired {
return 0.2
} else if currentIncomeRequired >= minIncomeRequired {
return (0.05 * Double(currentIncomeRequired / minIncomeRequired) )
}
}
public var toleranceFactor: Double {
switch tolerance {
case "conservative": return 0.0
case "balanced": return 3.0
case "aggressive": return 6.0
default: 0.0
}
}
public var outlookFactor: Double {
switch outlook {
case "poor": return 0.0
case "moderate": return 7.0
case "strong": return 10.0
default: return 0.0
}
}
public var stock: Double {
return maxAge - currentAge + currentAssetFactor + savingsFactor + toleranceFactor + outlookFactor
}
public var nonStock: Double { return 100.0 - stock }
public var bondPercentage: Double { return 0.35 + bondFactor }
public var bond: Double { return nonStock * bondPercentage }
public var cash: Double { return nonStock - bond }
// MARK: - Init
public init(currentAge: Double, currentAsset: Double, currentSavings: Double, currentIncomeRequired: Double, tolerance: String, outlook: String) {
assert(currentAge > 0)
self.currentAge = currentAge
self.currentAsset = currentAsset
self.currentSavings = currentSavings
self.currentIncomeRequired = currentIncomeRequired
self.tolerance = tolerance
self.outlook = outlook
}
}
答案 0 :(得分:1)
您没有涵盖所有案例。考虑一下你的方法:
public var currentAssetFactor: Double {
if currentAsset > maxCurrentAsset {
return 5.0
} else if currentAsset >= minCurrentAsset {
return Double(currentAsset / minCurrentAsset)
}
}
精细。那么,如果第一个if
失败(例如currentAsset
不大于maxCurrentAsset
)而第二个if
失败(例如currentAsset
} 不大于或等于minCurrentAsset
)?现在我们什么都不退货!
所以你的逻辑上有一个漏洞。编译器很聪明 - 比你聪明! 所以聪明,它会在你的逻辑中发现这个洞,并阻止你进入你的轨道。你需要以这样的方式重写你的方法,以便证明给编译器包含所有可能性,即你总是返回一个值,无论如何。< / p>