General question, why don't Java classes use enums?

[Anza Power]

For example alot of classes in Swing use static final integers like BorderLayout.NORTH, JFrame.EXIT_ON_CLOSE, why aren't they defined as enums? if they were enums it would be safer because you can detect errors like these during compile time:

SomeObject.setDirection(OtherObject.SOMETHIONG_UNR ELATED);

[pbrockway2]

I would guess that they predate enums. You could check the Enum API docs to see when they became available.

[Eranga]

I agreed because of two reasons,

1. Enums are much type-safe than integer and so on
2. They make codes more readable

[JosAH]

I agreed because of two reasons,

1. Enums are much type-safe than integer and so on
2. They make codes more readable

Changing all those magic numbers to enums would be a noble deed indeed, but it would break a lot of existing code ...

kind regards,

Jos

[Eranga]

Changing all those magic numbers to enums would be a noble deed indeed, but it would break a lot of existing code ...

kind regards,

Jos

Of course. I like to make my code more and more readable...

[JosAH]

Of course. I like to make my code more and more readable...

If you do it well and use those symbolic (int) constants and don't rely on the fact that they are ints, enums won't buy you much w.r.t. readablilty.

kind regards,

Jos

[Anza Power]

^ The most important thing is type-safty, some constants can be really confusing especially when they don't belong to the same class (like TOP vs NORTH)

Couldn't they just deprecate those methods (but keep them defined) and add copies of each method that uses enums?

[KevinWorkman]

^ The most important thing is type-safty, some constants can be really confusing especially when they don't belong to the same class (like TOP vs NORTH)

Couldn't they just deprecate those methods (but keep them defined) and add copies of each method that uses enums?

There are methods and then the values passed into those methods, and they're usually ints or Strings. In order to not break backwards compatibility, they'd have to add an enum version of each constant, as well as a new method for every method that accepts one of those values. I'd rather them spend their time on other stuff, as this is a non-issue that doesn't actually affect development.

If it bothers you so much, you could define your own enums that each contain a method that returns the corresponding value.

[Eranga]

If you do it well and use those symbolic (int) constants and don't rely on the fact that they are ints, enums won't buy you much w.r.t. readablilty.

kind regards,

Jos

I like to work with symbols a lot (may be because of C/C++ background). It gives me a more readable.

[Eranga]

some constants can be really confusing especially when they don't belong to the same class (like TOP vs NORTH)

Because of the way we named them.