Nested Select Case structures are difficult to understand because you can easily confuse the cases of an inner Select
Case as belonging to an outer statement. Therefore nested Select Case statements should be avoided.
Specifically, you should structure your code to avoid the need for nested Select Case statements, but if you cannot, then consider
moving the inner Select Case to another function.
Noncompliant code example
Public Sub Foo(A As Integer, B As Integer)
Select Case A
Case 0
' ...
Case 1
Select Case B ' Noncompliant; nested Select Case
Case 2
' ...
Case 3
' ...
Case 4
' ...
Case Else
' ...
End Select
Case 2
' ...
Case Else
' ...
End Select
End Sub
Compliant solution
Public Sub Foo(A As Integer, B As Integer)
Select Case A
Case 0
' ...
Case 1
HandleB(B)
Case 2
' ...
Case Else
' ...
End Select
End Sub
