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Re: Using Java Classes to Sort a Small Array Quickly

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On 01.09.2011 04:48, KevinSimonson wrote:
> I have an<enum>  named<ProjectEnum>  that has twelve values.  Today I
> added an instance variable to it, a<String>  named<collectionTitle>.
> The engineer I'm working with asked me to write a static method in
> class<ProjectEnum>  that returns an array of<ProjectEnum>s sorted
> alphabetically by this value<collectionTitle>.

Since we're talking about an enum and I am sure you made field "name" 
final (i.e. to make instances immutable) you can completely ignore sort 
performance.  You just need to sort once.  For example:

package en;

import java.util.Arrays;
import java.util.Comparator;

public enum ProjectEnum {

   P1("xyz"), P2("abc"), P3("def");

   private final String collectionTitle;

   private ProjectEnum(String name) {
     if (name == null) {
       throw new NullPointerException();
     }

     this.collectionTitle = name;
   }

   public String getCollectionTitle() {
     return collectionTitle;
   }

   private static final ProjectEnum[] sortedValues;

   static {
     sortedValues = ProjectEnum.values();

     Arrays.sort(sortedValues, new Comparator<ProjectEnum>() {
       @Override
       public int compare(ProjectEnum o1, ProjectEnum o2) {
         return o1.getCollectionTitle().compareTo(o2.getCollectionTitle());
       }
     });
   }

   public static ProjectEnum[] sorted() {
     return Arrays.copyOf(sortedValues, sortedValues.length);
   }
}

Kind regards

	robert

-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/

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Using Java Classes to Sort a Small Array Quickly KevinSimonson <kvnsmnsn@hotmail.com> - 2011-08-31 19:48 -0700
  Re: Using Java Classes to Sort a Small Array Quickly markspace <-@.> - 2011-08-31 20:39 -0700
    Re: Using Java Classes to Sort a Small Array Quickly bugbear <bugbear@trim_papermule.co.uk_trim> - 2011-09-01 09:18 +0100
    Re: Using Java Classes to Sort a Small Array Quickly Roedy Green <see_website@mindprod.com.invalid> - 2011-09-01 02:38 -0700
      Re: Using Java Classes to Sort a Small Array Quickly Patricia Shanahan <pats@acm.org> - 2011-09-01 03:50 -0700
    Re: Using Java Classes to Sort a Small Array Quickly Wanja Gayk <brixomatic@yahoo.com> - 2011-09-11 23:14 +0200
      Re: Using Java Classes to Sort a Small Array Quickly Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-09-11 17:53 -0400
        Re: Using Java Classes to Sort a Small Array Quickly Wanja Gayk <brixomatic@yahoo.com> - 2011-09-12 01:40 +0200
          Re: Using Java Classes to Sort a Small Array Quickly Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-09-11 20:32 -0400
          Re: Using Java Classes to Sort a Small Array Quickly Arne Vajhøj <arne@vajhoej.dk> - 2011-09-11 21:10 -0400
            Re: Using Java Classes to Sort a Small Array Quickly Lew <lewbloch@gmail.com> - 2011-09-11 20:30 -0700
              Re: Using Java Classes to Sort a Small Array Quickly Arne Vajhøj <arne@vajhoej.dk> - 2011-09-12 19:13 -0400
                Re: Using Java Classes to Sort a Small Array Quickly Lew <lewbloch@gmail.com> - 2011-09-12 17:42 -0700
                Re: Using Java Classes to Sort a Small Array Quickly Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-09-12 21:24 -0400
          Re: Using Java Classes to Sort a Small Array Quickly Gene Wirchenko <genew@ocis.net> - 2011-09-12 10:57 -0700
            Re: Using Java Classes to Sort a Small Array Quickly Arne Vajhøj <arne@vajhoej.dk> - 2011-09-12 19:01 -0400
              Re: Using Java Classes to Sort a Small Array Quickly Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-09-12 21:29 -0400
                Re: Using Java Classes to Sort a Small Array Quickly markspace <-@.> - 2011-09-12 19:49 -0700
                Re: Using Java Classes to Sort a Small Array Quickly Lew <lewbloch@gmail.com> - 2011-09-12 21:51 -0700
                Re: Using Java Classes to Sort a Small Array Quickly Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-09-13 11:32 -0500
                Re: Using Java Classes to Sort a Small Array Quickly Arne Vajhøj <arne@vajhoej.dk> - 2011-09-13 21:51 -0400
                Re: Using Java Classes to Sort a Small Array Quickly Patricia Shanahan <pats@acm.org> - 2011-09-13 06:33 -0700
              Re: Using Java Classes to Sort a Small Array Quickly Gene Wirchenko <genew@ocis.net> - 2011-09-13 09:48 -0700
  Re: Using Java Classes to Sort a Small Array Quickly Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-09-01 00:25 -0400
    Re: Using Java Classes to Sort a Small Array Quickly Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-09-01 00:54 -0400
    Re: Using Java Classes to Sort a Small Array Quickly bugbear <bugbear@trim_papermule.co.uk_trim> - 2011-09-01 09:20 +0100
      Re: Using Java Classes to Sort a Small Array Quickly Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-09-01 08:06 -0400
    Re: Using Java Classes to Sort a Small Array Quickly Roedy Green <see_website@mindprod.com.invalid> - 2011-09-01 02:43 -0700
  Re: Using Java Classes to Sort a Small Array Quickly Robert Klemme <shortcutter@googlemail.com> - 2011-09-01 08:32 +0200
  Re: Using Java Classes to Sort a Small Array Quickly RedGrittyBrick <RedGrittyBrick@spamweary.invalid> - 2011-09-01 10:08 +0100
    Re: Using Java Classes to Sort a Small Array Quickly Patricia Shanahan <pats@acm.org> - 2011-09-01 04:02 -0700
  Re: Using Java Classes to Sort a Small Array Quickly Roedy Green <see_website@mindprod.com.invalid> - 2011-09-01 02:37 -0700
  Re: Using Java Classes to Sort a Small Array Quickly Roedy Green <see_website@mindprod.com.invalid> - 2011-09-01 04:53 -0700
  Re: Using Java Classes to Sort a Small Array Quickly Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-09-01 09:05 -0500

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