Re: Simple question about Java Methods

Mark Space <>
Mon, 18 Aug 2008 12:22:27 -0700
Danger_Duck wrote:

Doh!, I guess enumerations in Java aren't as bad as I thought, in
addition to not being able to interchange them with integers, I was
always turned off by the below link, but turns out that I misread it:

That there is some pretty complex use of enums.

All you really need is:

   enum Waves { sine, square, sawtooth }

Then you can do things like specify them as parameters to your method

   public void method1( Waves w ) {
         switch (w) {
             case sine:
             // Draw a sine wave
             case square:
             // Draw a square wave
             case sawtooth:
             // Draw a sawtooth wave

This is pretty unsophisticated use of enums, but it works. If you don't
like the examples up-thread (which are better, btw) then this will work
just fine until you get used to doing more tricky things with enums.

I had thought that a client program had to instantiate an instance of
the enumeration, then call a method on it. Now I realize that I
thought the class "EnumTest" was the enumeration :)

Nope, you don't have to do that if you don't want to. You can, and it
can often be better to do so, but if you don't understand it then I
would just concentrate on writing code you understand and can maintain
and worry about the tricky stuff later.

While I still don't like how Java does not provide direct access to
the enumeration like in C, your way works fine for what I want here,
and it looks like I was too quick to bash what I had in fact misread.

What kind of direct access are you looking for? It's easy to concert
enums into integers: sine.ordinal() will convert "sine" into a number. I
don't see immediately how to go in the other direction, but I think
Waves.values() will always return an array in ordinal order.

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