How do I create an enum-like object with string values?

Question

i'm working on parsing a text project where in , i have to match the match the text and get the keywords from the text and perform some actions accordingly.

Now , i'm trying to use enum for matching the text Eg. all the conditions, any condition, none, alteast one,and or etc. i'm trying use enum as the key words might change later, Is it possible to store string values in enum.

public enum condition 
{ 
    type1 = "all the conditions", 
    type2 = "any of the conditions" 
}

i know it is not like normal enum usage,can any one help

Community · Accepted Answer · 2017-05-23 10:24:24Z

4

You could use readonly string properties:

public class Condition
{
    public static readonly string Type1 = "All_The_Conditions";
    public static readonly string Type2 = "Any_Conditions";
}

Use it like this:

if(condition_variable == Condition.Type1)//will do a string compare here.
{
 ...
}

BUT

This above solution would however NOT work with switch statements. In which case you could use const

public class Condition
{//this could be a better solution..
    public const string Type1 = "All_The_Conditions";
    public const string Type2 = "Any_Conditions";
}

You could use it like this:

switch (condition_variable)
{
    case Condition.Type1://can only be done with const
     ....
    break;
}

See this post for static readonly vs const variables.

To Expand on enums (See MSDN):

They have a default underlying type of int. You can change the underlying type to one of the following integral types : byte, sbyte, short, ushort, int, uint, long, or ulong.

Thanks to @Bryan and @R0MANARMY for helping me improve my answer.

edited May 23, 2017 at 10:24

CommunityBot

11 silver badge

answered Mar 1, 2012 at 4:32

gideon

19.5k11 gold badges74 silver badges114 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Bryan Watts Over a year ago

+1 Enumerations are numeric types by definition, so they don't support strings. It might be worthwhile to mention that you can't use this solution with switch statements.

gideon Over a year ago

@BryanWatts excellent catch. R0MANARMY yep was thinking on the same lines and updated the question :)

gideon Over a year ago

@R0MANARMY ah typo, I copy pasted the prev code block, Fixed it. (I used something like this in a project I have opened at the moment ;)

Yuval Peled · Accepted Answer · 2012-03-01 04:48:06Z

3

You can use a dictionary instead to map from the enum (key) to string (value). Something like:

Dictionary<Condition, string> dict = new Dictionary<Condition, string>(); 
dict[Condition.Type1] = "all the conditions";

[Edit]: Actually, now that I read your question more carefully I would do it the other way around. The mapping should be from the string to the condition and then you should compare the text to the key value (string) and if it matches you get the enum value. i.e:

   Dictionary<string, Condition> dict = new Dictionary<string, Condition>(); 
   Condition result = Condition.Invalid;

   bool isFound = dict.TryGetValue(someTextToParse, out result);

Makes sense?

edited Mar 1, 2012 at 4:48

answered Mar 1, 2012 at 4:33

Yuval Peled

5,0388 gold badges33 silver badges36 bronze badges

5 Comments

Roman Over a year ago

You'd have to test to see if the key is in the dictionary to avoid runtime exceptions. It might just serve to obscure the intent of the code.

StuartLC Over a year ago

Yes, and given that OP needs to parse text, why not have the string (or a hash thereof) as the key. The enum key can then be mapped e.g. with TryGetValue msdn.microsoft.com/en-us/library/bb347013.aspx

M.Babcock Over a year ago

This seems awfully heavy compared to the behavior the OP is asking for.

Roman Over a year ago

I would argue it obscures the intent a little bit. A lookup table implies the text options aren't fixed, seeing a bunch of if or a switch statement implies the number of text options if fixed. Either option would work.

Yuval Peled Over a year ago

It depends also on the number of words that he has to match against. Dictionary consumes more space but it's O(1) retrieval instead O(N).

M.Babcock · Accepted Answer · 2012-03-01 04:40:29Z

0

I was under the impression that enum definitions had to contain numerical values, though I could be wrong.

An alternative way to handle this is with a simple array of struct objects:

struct ConditionKeywords
{
    int Key;
    string Value;
}
ConditionKeywords[] keyword = { new ConditionKeywords { Key = 1, Value = "all the conditions } /* ... */ };

And a simple enumeration which can be accessed in code:

enum ConditionValues
{
    type1 = 1;
}

Of course this has the potential to have multiple strings which mean the same key which is a double edge sword, so a simpler approach could be:

string[] ConditionKeywords { "all the conditions" /* ... */ }

using the same enumeration approach above (only limiting it to only valid indexes in ConditionKeywords).

answered Mar 1, 2012 at 4:40

M.Babcock

19k6 gold badges57 silver badges85 bronze badges

2 Comments

M.Babcock Over a year ago

Wow, I missed a lot while typing my answer.

gideon Over a year ago

I know the feeling! (From most other questions)

Collectives™ on Stack Overflow

How do I create an enum-like object with string values?

3 Answers 3

3 Comments

5 Comments

2 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

3 Comments

5 Comments

2 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related