To control whether or not a part of the script should run can be done by an IF block or
a SELECT block. The IF block is the simplest way. The If keyword will test a
rule, if it returns true then it will run that part of the script between the If and End
If keywords. My last sentence actually had an "if" concept, like this:
If A = 1 Then
'Run This
'only if A = 1
End If
If the rule returns false, it can either not run that part of the script or run a
different part:
If A = 1 Then
'Run This
'only if A = 1
Else
'Run This
'only if A did not = 1
End If
If the rule was false you can also give other rules, only if the main rule was false
and if all other rules are false then run a final part of code:
If A = 1 Then
'Run This
'only if A = 1
ElseIf B = 1 Then
'Run This
'only if B = 1, and A did not = 1
ElseIf A = 2 Then
'Run This
'only if A = 2, A did not = 1, and B did not = 1
Else
'Run This
'only if A did not = 1 or 2, and B did not = 1
End If
Simple, sometimes, but if you get into many ElseIfs where the rule uses the same
variable, then a SELECT block is a good idea. SELECT will run a set of tests on the
same variable and run a bit of code for the tests that are true. To specify a test
you use the CASE command. If all tests (CASE commands) are false, it can continue without running the
code from any rules or run a code when all rules come back false. This is marked
with CASE ELSE. The end of the a SELECT block is END SELECT.
Example:
Select
VariableA
Case 5
'Run if VariableA = 5
Case < 2
'Run if
VariableA < 2
Case Else
'Run if other rules didn't apply
End Select
