CODEWITHSUNDEEP
java
RenaultH
RenaultH

Reputation: 21

How to store more than one option in a variable - Java

In Java, how would I create a property/field/variable that can at any one time store a couple of options/values, similar to lower level environments where you can set bits in variables, each meaning different things. I know that one can do this in Java by using static finals or something and then just ORing them all together, but isn't there a more elegant solution? E.g in C# where you can have the [Flags] attribute to an Enum and then OR the states/values together into an instance of that Enum.

Any ideas?

Renault

Upvotes: 2

Views: 389

Answers (3)

Sean Patrick Floyd
Sean Patrick Floyd

Reputation: 299008

The old-fashioned way (that you can still find in many libraries) would be to encode a bit mask using either an int value or a BitSet, but since JDK 1.5, an EnumSet is the preferred way to do it, as Jon Skeet says.

Upvotes: 1

Joe Kearney
Joe Kearney

Reputation: 7537

You mean like a C++ union? This is not allowed in Java because you lose type safety; this would allow you to get a reference to an Integer typed as a String, for example.

Upvotes: 0

Jon Skeet
Jon Skeet

Reputation: 1501586

Well, you can use an enum and then have an EnumSet for that enum. It's hard to know exactly what to recommend without more information. EnumSet is a good choice when you're naturally dealing with just "options" - but if you have multiple values (e.g. height and width; a fixed number of values which just naturally come together) then I'd just create a new type to encapsulate them.

If you could give concrete examples of what you're looking for, we may be able to help more.

Upvotes: 7

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