函数中缺少返回 - 模型中的swift错误

时间:2015-04-22 17:25:47

标签: ios swift struct model compiler-errors

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
  }

}

1 个答案:

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 大于maxCurrentAsset)而第二个if失败(例如currentAsset } 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>

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