How to make multiple variations on case

Question

I'm using delphi to run the following code:

if (number> 8) and (number< 10) then
    message:= 'first option'
else if (number> 11) and (number< 17) then
    message:= 'second option'
else if (number> 18) then
    message:= 'third option';

I need to do the exact code but using case, I am trying but didn't find any content that explains how to do it:

case idade of
(case > 8 and case< 10) : message:= 'first option';
(case > 11 and case< 17) : message:= 'second option';
(case > 18) : message:= 'third option';
end;

I've tried to search for questions about case as well, but I guess I didn't find the correct way to find for this answer as well.

Answer 1

The closest you can get to that result using a case statement would look like this:

case idade of
  9: message := 'first option';
  12..16: message := 'second option';
else
  if idade > 18 then
    message := 'third option';
end;

Or this (thanks @AndreasRejbrand):

case idade of
  9: message := 'first option';
  12..16: message := 'second option';
  19..MaxInt{idade.MaxValue}: message := 'third option';
end;

You might want to read Embarcadero's documentation on how Case Statements actually work.

Do note that in the original code, if (number> 8) and (number< 10) then is the same as if (number = 9) then, and you are skipping the assignment of message if number is either 10, 17, or 18, is that what you really want?