Question

Given an enumerated type declaration in Delphi such as:

TMyType = (Item1, Item2, Item3);

is there any way to add a fourth item, say Item4, to the enumerate type at runtime so that
at some point during the application’s execution I have:

TMyType = (Item1, Item2, Item3, Item4);

Or are types fixed in Delphi?

Answer 1

No, you ‘can’t’ do this. It is against the way Delphi works. (Recall that Delphi checks your types already at compile time.)

If I were you, I’d not do

TComputerType = (ctDesktop, ctServer, ctLaptop, ctNetbook, ctTablet)

Instead, I’d do

TComputerType = integer;

const
  COMPUTER_TYPE_DESKTOP = 0;
  COMPUTER_TYPE_SERVER = 1;
  COMPUTER_TYPE_LAPTOP = 2;
  COMPUTER_TYPE_NETBOOK = 3;
  COMPUTER_TYPE_TABLET = 4;

I am sure you get why.