Visual Basic and Visual FoxPro Case statements
VBA
Select Case, Case, Case Else, End Select
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VFP
Do Case, Case, Otherwise, End Case
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At first sight these structures look very similar but there is a deep difference between
the two.
Visual Basic Syntax Notes
The cases in Visual Basic must all refer to the same variable. This variable is stated
in the first line of the structure and each case merely specifies a value or a range of
values for that variable. If none of these values match then the code in the
Case Else clause is executed.
Select Case CustomerType
Case 1
Status = "Delivery is free for category 1."
Case 3 To 5
Status = "Delivery is £1.00 for categories 3, 4 and 5."
Case Else
Status = "Delivery is £10.00 for everyone else."
End Select
The variable controlling the structure can be of any text, numeric or date type.
Visual FoxPro Syntax Notes
Each case in a Visual FoxPro Do Case structure has its own
independent logical test which allows for a lot more flexibility. If none of these
tests evaluate as true then the code in the Otherwise clause
is executed.
Do Case
Case Price > 1000
Status = "Delivery is free over £1,000."
Case CustomerType >= 3 And
CustomerType <= 5
Status = "Delivery is £1.00 for categories 3, 4 and 5."
Otherwise
Status = "Delivery is £10.00 for everyone else."
EndCase
The conditions for each case in a Visual FoxPro Case structure can be anything that
returns a boolean. There is no special syntax for a range equivalent to the "3 To 5" in
VB but FoxPro has the flexibility to use an And to combine
two comparisons in the statement.
Common Syntax
Only a single case will execute in the structure in both languages. Neither
implements a Java style fall-through execution.
The final Case Else or Otherwise
clause is optional but it's always a wise precaution to include it. Even if it just says:
...
Otherwise
Status = "This status is not possible."
EndCase
If
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