Enumeration

[NoteMe]

Is there any no enumeration in Java? Or something similar. Can't find anything...


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[Dillinger4]

Yes Java 5.0 added enums which are now a type of their own.

[Dillinger4]

I haven't checked them out though but probably a lot better than the old way.

/* Enum types the old style */

 public class BlenderOldStyle{

 public static final int SpeedSetting_off = 0;  
 public static final int SpeedSetting_low = 1;
 public static final int SpeedSetting_med = 2;
 public static final int SpeedSetting_high = 3; 

 }

[brown monkey]

public class test{
    public enum morons{noteme,
        mendhak,
        dsheller,
        electroman,
        plenderj,
        unfortunately_me,
        etcetera};
    public test(){
        System.out.println(morons.noteme.toString());
    }
    public static void main(String[] args){
        new test();
    }
}

[Dillinger4]

November issue 11 vol 9 of JDJ has an interesting article on enums in jdk5.0. After getting half way through it seems that some ofthe sorce code is not listed in the magazine(Listings 2-9 can be dl from http://sys-con.com/story/?storyid=46981&DE=1#RES) but the link contains the full article and the source. Give it a read. It's sounds interesting.

[Dillinger4]

I wanted to try out how enums work in the jdk5.0 so i did the following. Don't know if this is the right way to use them but i took a shot anyway.

/* Enum types the old style */
/*
 class BlenderOldStyle{

 public static final int SpeedSetting_off = 0;  
 public static final int SpeedSetting_low = 1;
 public static final int SpeedSetting_med = 2;
 public static final int SpeedSetting_high = 3; 
 private int currentsetting = SpeedSetting_off; 

 public void setSetting(int setting){
  currentsetting = setting; 
 }

 public void checkCurrentSetting(){
  printCurrentSetting(currentsetting); 
 }

 private void printCurrentSetting(int currentsetting){
   switch(currentsetting){
    case 0:
    System.out.println("Blender is off");
    break; 
    case 1:
    System.out.println("Blender is on low"); 
    break; 
    case 2:
    System.out.println("Blender is on med"); 
    break; 
    case 3:
    System.out.println("Blender is on high");
    break;  
   }
  }
 }
 
 public class BlenderX{
  public static void main(String[] args){

   BlenderOldStyle bos = new BlenderOldStyle(); 
   bos.checkCurrentSetting(); 
   bos.setSetting(bos.SpeedSetting_med); 
   bos.checkCurrentSetting();
  }
 }
*/
/* new style jdk5.0 */
 class Blender{
  public enum SpeedState{Off,Low,Med,High};
  private SpeedState currentState = SpeedState.Off;

  public void setState(SpeedState state){
    currentState = state ;
  }
   public SpeedState getNextSpeed(){
    switch (currentState) {
     case Off: return SpeedState.Off;
     case Low: return SpeedState.Low;
     case Med: return SpeedState.Med;
     case High: return SpeedState.High;
    }
    return null ;
   }
  public void printStates() {
   for(SpeedState state: SpeedState.values()){
     System.out.println(state);
   }
  }
 }
 public class BlenderX{
  public static void main(String[] args){
   Blender bl = new Blender(); 
   System.out.println(bl.getNextSpeed());
   bl.setState(Blender.SpeedState.Med);
   System.out.println(bl.getNextSpeed());
  }
 }

[NoteMe]

Yeah, that was intresting, thanks. But they don't seem to have 5.0 at school, so no help actualy. So I had to do it the hard way. Thanks anyway.



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[Dillinger4]

I actualy think using static final fields is a lot easier even if it does lack some of the benefits of having an enum type.

[NoteMe]

I actualy think using static final fields is a lot easier even if it does lack some of the benefits of having an enum type.

Much more to write, and I am used with Enums from C++, so it kind of irritates me. But nothing to do about it.


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[CornedBee]

Enums provide type safety, string conversion, less writing, what else do you want?

[Dillinger4]

Posted by NoteMe

Much more to write, and I am used with Enums from C++, so it kind of irritates me. But nothing to do about it.

Sure there is somthing to do about it. Just use enums from java 5.

[CornedBee]

Dilenger, he said he can't use Java 5 at school.

[Dillinger4]

Too bad.