Search code examples
excelboolean-operationsselect-casevba

select case with variable boolean operator

This is my first question on the forum, but reading previous questions has been enormously helpful in the project I'm working on, so already my thanks. I couldn't find an answer to this, but apologies if I overlooked something.

I am writing an excel macro in vba, and am trying to create a select case... statement in which the expression has a variable boolean and numeric component. For example, the macro can pull "> 3" or "< 3" from another worksheet.

My hope had been that I could assign to a string all of these parameters, i.e.:

test1 = "is " & BoolOperator1 & " " & NumericValue1

and then

Select case ValuetoCompare
    Case test1
      'Do something
    Case test2
       '...

Is there a way to do this? I suppose the alternative would be to nest the case with the numeric variable inside a select function that determines the operator, but I thought this would be more elegant.

Thanks in advance for your guidance--

Josh

Solution

  • Assuming that you'll get a string BoolOperator1 that is a valid operator, e.g. >=, =, and a numeric value NumericValue1, the easiest way to execute this comparison on another numeric value ValueToCompare is to use the Evaluate function. This will execute a string as VBA and return it's result.

    In your case, you could simply use:

    If Evaluate(ValueToCompare&BoolOperator1&NumericValue1) Then ...

    If you want to use this in a Select Case statement, you'd either need to use a simple If ... ElseIf ... statement - or use this trick:

    Select Case True
    Case Evaluate(ValueToCompare&BoolOperator1&NumericValue1): ...
    Case Evaluate(ValueToCompare&BoolOperator2&NumericValue2): ...
    Case Else ...
End Select