How to import another Enum into My Enum

Question

This is my Enum

public enum MyEnum {Blue, Red};

There is another external enum called ExternalEnum, I don't have and couldn't change its source code but I can use the class, say I know there are yellow and white in it.

What I want to do is to pull all the elements in the external enum, make them part of my enum, i.e.

public enum MyEnum {Blue, Red, ExternalEnum.Yellow, ExternalEnum.White};

Is there a way I can do this easily so each time I get a new version of ExternalEnum I don't need to manually go over all its elements? I don't want to use extend (subclass) as they belong to different package.

Thanks!

"Package" suggests that it's java, but "extend" confuses me. Do you wish to dynamically update the values in this "enum"? — Cambium, Jul 15 '10 at 02:09
+1 Daniel - without knowing the intended language (which we can guess at, but not be certain), how can we help? — Mawg says reinstate Monica, Jul 15 '10 at 02:34
You are welcome. Also, since you are new to StackOverflow, I would like to inform you that you can upvote good answers and accept the answer that helped you the most by checking the tick mark next to the Answer. On this site an upvote or an accepted answer counts as a "thanks". — Olivier Jacot-Descombes, Dec 27 '12 at 17:30

score 2 · Answer 1 · edited May 23 '17 at 11:55

2

What you are talking about is a "Dynamic Enum".

Here is a link to a previous question here at StackOverflow.

edited May 23 '17 at 11:55

Community

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1

answered Jul 15 '10 at 02:03

saunderl

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+1 for a good reference, but that one is C# specific and OP hasn't specified a language. It also doesn't have an accepted answer yet. OP, which language are you targetting? – Mawg says reinstate Monica Jul 15 '10 at 02:36

score 2 · Answer 2 · answered Nov 24 '11 at 15:52

You can do it by redefining the enum constants like this:

public enum ExternalEnum
{
    White, // -> 0
    Black  // -> 1
}

public enum MyEnum
{
    White = ExternalEnum.White, // -> 0
    Black = ExternalEnum.Black, // -> 1
    Red, // -> 2
    Blue // -> 3
}

However, you must ensure that the integer values of the enum constants do not overlap. The easiest way of doing it, is to declare the external constants first. There is no such thing like an automatic import into enums. You cannot extend enums.

Mawg says reinstate Monica · Answer 3 · 2010-07-15T05:32:54.743

1

Since you don't specify a lnguage it is very difficult to help you, but I suspect that what you want to do might be easier in interpreted languages than compiled.

edited Jul 15 '10 at 05:32

answered Jul 15 '10 at 02:37

Mawg says reinstate Monica

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How to import another Enum into My Enum

3 Answers3