Reputation: 205

Delphi and enum

Does Delphi have an analog of enum in C?

Upvotes: 14

Answers (4)

Wolf

Reputation: 10238

In addition to the positive responses that are focused on the parallels, there are

Some restrictions:

1. Anonymous enumerations are not supported in Delphi.

So you have to translate

enum { SOME_CONSTANT = 42 };

into

const
  SOME_CONSTANT = 42

… which is, by the way, a better wording for your actual intent. But unfortunately, this can be translated back into something different. At least C++Builder 6 translates it like this in the auto-generated *.hpp file:

static const Shortint SOME_CONSTANT = 0x2A;

2. Explicit enum values were added with Delphi 6.

The feature of explicitly adding values to enumerators was introduced with Delphi 6. So you have to switch to normal constants, see this answer to How to create an enum with explicit values in Delphi 5 for more.

3. Finally, a restriction of C:

In C, enumerations are just compile-time constants that are implicitly converted into int as needed. This is basically where the support ends. Delphi has a stronger typing but provides information about the valid range and also iteration, see this snippet:

procedure TForm1.Button1Click(Sender: TObject);
type
  TMyEnum = (meOne, meTwo, meThree);
var
  v: TMyEnum;
  txt: String;
begin
  for v := Low(TMyEnum) to High(TMyEnum) do
    txt := txt + IntToStr(Integer(v)) + ' ';
  ShowMessage(txt)
end;

Upvotes: 2

da-soft

Reputation: 7750

Yes, Delphi has the following enumerated type construction:

type
  TDigits = (dgOne, dgTwo, dgThree <etc>);

Also, like in C, each symbol of an enumerated type may have a specified value, like this:

type
  TDigits = (dgOne = 1, dgTwo, dgThree <etc>);

Upvotes: 47

Justin Niessner

Reputation: 245429

Yes. Check out the first portion of Delphi Basics: Enumerations, SubRanges, and Sets.

Upvotes: 9

Adriaan Stander

Reputation: 166396

Have a look at

Enumerations, SubRanges and Sets

Upvotes: 5