减少选择中的循环复杂度

Question

Good day coding godz，

我正在尝试清理一些代码，并想知道如何降低我创建的方法的循环复杂性。此方法用于导入CSV文件。CSV文件中的一个字段是一个许可证类型，它是一个字符串(即"BFI监管贷款人-网站#2许可证"(。我正在将其转换为一个整数(1,2,3或4(，该整数将保存到数据库中，以根据许可证类型引用行业类型。

下面是我的方法。非常感谢一些关于荫树VB.NET编码器的提示。。。

Private Function CheckIndustryType(LicName)
Dim VAR_IndType As Integer
Select Case Text_LicName
Case "BFI Level I Check Cashing - Branch License"
VAR_IndType = 3
Case "BFI Level II Check Cashing - Branch Certificate"
VAR_IndType = 3
Case "BFI Supervised Lender - Branch License"
VAR_IndType = 1
Case "BFI Deferred Presentment - Branch License"
VAR_IndType = 3
Case "BFI Supervised Lender - Website #1 License"
VAR_IndType = 1
Case "BFI Supervised Lender - Website #2 License"
VAR_IndType = 1
Case "BFI Supervised Lender - Website #3 License"
VAR_IndType = 1
Case "BFI Supervised Lender - Website #4 License"
VAR_IndType = 1
Case "BFI Supervised Lender - Website #5 License"
VAR_IndType = 1
Case "BFI Supervised Lender - Website #6 License"
VAR_IndType = 1
Case "BFI Level II Check Cashing - Company License"
VAR_IndType = 3
Case "BFI Level I Check Cashing - Company License"
VAR_IndType = 3
Case "fI Branch Mortgage Lender/Servicer"
VAR_IndType = 2
Case "BFI Branch Mortgage Lender/Servicer - Other Trade Name #1"
VAR_IndType = 2
Case "BFI Branch Mortgage Lender/Servicer - Other Trade Name #2"
VAR_IndType = 2
Case "BFI Branch Mortgage Lender/Servicer - Other Trade Name #3"
VAR_IndType = 2
Case "BFI Branch Mortgage Lender/Servicer - Other Trade Name #4"
VAR_IndType = 2
Case "BFI Branch Mortgage Lender/Servicer - Other Trade Name #5"
VAR_IndType = 2
Case "BFI Branch Mortgage Lender/Servicer - Other Trade Name #6"
VAR_IndType = 2
Case "BFI Mortgage Lender / Servicer License"
VAR_IndType = 2
Case "BFI Mortgage Lender/Servicer License - Other Trade Name #1"
VAR_IndType = 2
Case "BFI Mortgage Lender/Servicer License - Other Trade Name #2"
VAR_IndType = 2
Case "BFI Mortgage Lender/Servicer License - Other Trade Name #3"
VAR_IndType = 2
Case "BFI Mortgage Lender/Servicer License - Other Trade Name #4"
VAR_IndType = 2
Case "BFI Mortgage Lender/Servicer License - Other Trade Name #5"
VAR_IndType = 2
Case "BFI Mortgage Lender/Servicer License - Other Trade Name #6"
VAR_IndType = 2
Case Else
VAR_IndType = 4
End Select
Return VAR_IndType 
End Function

Answer 1

在这种情况下，我会使用字典。它将独立路径的数量减少到2，第二个路径是必要的，因为您当然使用默认值。

Module Module1
Dim industryTypeMap As New Dictionary(Of String, Int32) From {{"BFI Level I Check Cashing - Branch License", 3},
     {"BFI Level II Check Cashing - Branch Certificate", 3},
     {"BFI Supervised Lender - Branch License", 1}}
Sub Main()
Console.WriteLine(CheckIndustryType("BFI Supervised Lender - Branch License"))
Console.WriteLine(CheckIndustryType("BFI Level II Check Cashing - Branch Certificate"))
Console.WriteLine(CheckIndustryType("Other"))
End Sub
Private Function CheckIndustryType(LicName As String)
Dim industryInt As Int32
If industryTypeMap.TryGetValue(LicName, industryInt) Then
Return industryInt
Else
Return 4
End If
End Function
End Module

该输出：

1
3
4

您也可以在函数中定义字典来将所有代码维护在一起，但如果您重复调用函数，那么运行速度显然会较慢。

根据下面的注释-理想情况下，您应该将实际映射放置在一个外部项中，该项可以在不重新编译代码的情况下进行更新(例如配置文件或数据库(。

Answer 2

我通过使用StartsWith和Contains以及Select Case True来缩短病例数。

Private Function CheckIndustryType(LicName As String) As Integer
Dim VAR_IndType As Integer
Select Case True
Case LicName.Contains("Check Cashing")
VAR_IndType = 3
Case LicName.StartsWith("BFI Supervised Lender")
VAR_IndType = 1
Case LicName.StartsWith("BFI Deferred Presentment")
VAR_IndType = 3
Case LicName.StartsWith("fI")
VAR_IndType = 2
Case LicName.StartsWith("BFI Branch Mortgage Lender")
VAR_IndType = 2
Case Else
VAR_IndType = 4
End Select
Return VAR_IndType
End Function

Answer 3

长字符串列表是有风险的，因为任何更改都很可能导致拼写错误，然后字符串不匹配。我可能会做一个Enum:

Enum LicenseType
BFILevelICheckCashingBranchLicense
BFILevelIICheckCashingBranchCertificate
BFISupervisedLenderBranchLicense
...
End Enum

然后对照该值进行测试。为了降低复杂性，我会制作一个属性，如：

Class VarIndTypeAttribute 
Inherits System.Attribute
Public VarIndType As Integer
Sub New(varIndType As Integer
Me.VarIndType = varIndType
End Sub
End Class

然后枚举变为：

Enum
<VarIndType(3)>
BFILevelICheckCashingBranchLicense
<VarIndType(3)>
BFILevelIICheckCashingBranchCertificate
<VarIndType(1)>
BFISupervisedLenderBranchLicense
...
End Enum

然后你做一个类似的方法

<Extension>
Function ToVarIndType(enumValue As [Enum]) As Integer
Dim att = enumValue.GetAttributeOfType(Of VarIndTypeAttribute)()
Return If(att IsNot Nothing, att.VarIndType, 0)
End Function

然后

Dim valueEnum As LicenseType = ...
Dim VarIndType = valueEnum.ToVarIndType

而且您根本不需要查找功能！

您可能希望VarIndType也成为Enum，这样整个应用程序中就不会有像0和3这样的神奇值。