Re: How do I convert an int to an enum?

From:
Robert Klemme <shortcutter@googlemail.com>
Newsgroups:
comp.lang.java.programmer
Date:
Mon, 18 Sep 2006 13:29:41 +0200
Message-ID:
<4n7e95F900kuU1@individual.net>
On 18.09.2006 12:32, qu0ll wrote:

"Michael Rauscher" <michlmann@gmx.de> wrote in message
news:eelr7q$2p8q$1@registered.motzarella.org...

qu0ll schrieb:

Is this the way to do it? Now to convert all I do is:

ReturnValue x = ReturnValue.convert(method());

But this seems silly to have to define the int values of each enum value
effectively twice. Is there a better (simpler) way?

public static ReturnValue convert( int value ) {
    ReturnValue result = null; // or: = ReturnValue.UNDEFINED
    ReturnValue values[] = ReturnValue.values();
    int i = 0;
    while ( i < values.length && result == null )
        if ( values[i].value == value )
            result = values[i];
        else
            i++;

    return result;
}

Bye
Michael


Thanks, that's a neat solution. I didn't realise there was a values()
method.


IMHO there are neater solutions:

package enums;

public enum ReturnValue {

     POSITIVE, NEGATIVE, EITHER, UNDEFINED;

     public static ReturnValue convert1( int i ) {
         for ( ReturnValue current : values() ) {
             if ( current.ordinal() == i ) {
                 return current;
             }
         }

         return UNDEFINED;
     }

     public static ReturnValue convert2( int i ) {
         return values()[i];
     }

     public static ReturnValue convert3( int i ) {
         try {
             return values()[i];
         } catch ( ArrayIndexOutOfBoundsException e ) {
             return UNDEFINED;
         }
     }

     public static ReturnValue convert4( int i ) {
         final ReturnValue[] v = values();
         return i >= 0 && i < v.length ? v[i] : UNDEFINED;
     }
}

- no explicit int needed, enum comes with ordinal() already
- less complex conversion

Kind regards

    robert

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