Converting a method argument into an enum

Question

I have an enum type defined like so:

public enum Status
{
    Active=1,
    InActive=0
}

in my method can I cast the parameter into the enum like this:

public string doSomething(string param1, int status)
{
//will this work?      
Account.Status = (Status) status;
//or do i need to test one by one like this
if(status == 0)
{
 Account.Status = Status.Inactive;
 //and so on...
} // end if
}  // end doSomething

@Kaf Possible reason: he's using a database that supports `int`, but not `enum`. — Nolonar, Aug 22 '13 at 14:14
Yes, it will work. However, It's best to check if int is in the range of declared enum first. — VsMaX, Aug 22 '13 at 14:16
i ran the code...the compiler didnt complain.what happens when a value thats not in the enum is passed in? — sirbombay, Aug 22 '13 at 14:17
@MichaelCwienczek ok so i can just do a check for the range first as opposed to doing multiple ifs? — sirbombay, Aug 22 '13 at 14:20
@sirbombay you should be able to try that yourself quite easy... — Magnus, Aug 22 '13 at 14:20
because its inside a web service and...no excuse i'll find out myself.thanks everyone including those who angrily downvoted :) — sirbombay, Aug 22 '13 at 14:25

James · Answer 1 · 2013-08-22T15:11:27.583

2

Yes, you can do a straight cast from int to enum (given that an enum representation of that integer exists).

If you need to check whether the enum exists before parsing use Enum.IsDefined i.e.

if (Enum.IsDefined(typeof(Status), status))
{
    Account.Status = (Status)status;
}

edited Aug 22 '13 at 15:11

answered Aug 22 '13 at 14:08

James

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what happens when it doesnt exist? – sirbombay Aug 22 '13 at 14:18
The variable being assigned reverts to `int` - both types are interchangeable so you won't get an exception. – James Aug 22 '13 at 14:28

No Idea For Name · Answer 2 · 2013-08-22T14:24:44.233

1

well of course you can do that. just try and see.

you can also cast the other way

(int)Account.Status

it's possible to cast Enum to int and vice versa, because every Enum is actually represented by an int per default. You should manually specify member values. By default it starts from 0 to N.

if you try to convert an enum value that does not exist it'll work, but wont give you an enum value if you try to compare it the any value you have in the enum

edited Aug 22 '13 at 14:24

answered Aug 22 '13 at 14:11

No Idea For Name

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I actually tried it..it compiled fine.but my worry is what happens when a value is passed in that doesnt exist in the enum? – sirbombay Aug 22 '13 at 14:16
@sirbombay You can try that 2 :) – No Idea For Name Aug 22 '13 at 14:20
@sirbombay read my edited answer – No Idea For Name Aug 22 '13 at 14:25
it now makes sense...i guess i shd find that out myself too :) – sirbombay Aug 22 '13 at 14:30

Alex Siepman · Accepted Answer · 2013-08-22T15:17:49.387

1

Just check if the int is a valid value for Status and then do a conversion.

public string doSomething(string param1, int status)
{
    if (IsValidEnum<Status>(status))
    {
        Account.Status = (Status)status;
    }
    ...
}

private bool IsValidEnum<T>(int value)
{
    var validValues = Enum.GetValues(typeof(T));
    var validIntValues = validValues.Cast<int>();
    return validIntValues.Any(v => v == value);
}

In de else of the if you can throw an exception if you wish.

edited Aug 22 '13 at 15:17

answered Aug 22 '13 at 14:44

Alex Siepman

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i guess this is the magic i was looking for...thanks – sirbombay Aug 22 '13 at 14:59
`Enum.IsDefined` already does this - see my answer. – James Aug 22 '13 at 15:13
@James, Ok, it was fun to create the method but unneseccary... – Alex Siepman Aug 22 '13 at 16:28

Converting a method argument into an enum

3 Answers3