enum.values() - is an order of returned enums deterministic

java enums specifications
Skarab picture Skarab · Sep 29, 2010 · Viewed 30.6k times · Source

I have a enum SOME_ENUM: 

public enum SOME_ENUM {
  EN_ONE,
  EN_TWO,
  EN_THREE;
}

Will SOME_ENUM.values() always return the enums in the order of enum declarations: EN_ONE, EN_TWO, EN_THREE? Is it a rule or it is not guaranteed to be not changed in the next JDK releases?

Answer

GaryF picture GaryF · Sep 29, 2010

The Java language specification uses this explicit language:

@return an array containing the constants of this enum type, in the order they're declared [Source]

So, yes, they will be returned in declaration order. It's worth noting that the order might change over time if someone changes the class so be very careful about how you use this.

Related questions

How to get an enum value from a string value in Java?

Say I have an enum which is just public enum Blah { A, B, C, D } and I would like to find the enum value of a string, for example "A" which would be Blah.A. How would it be possible …

Read More
Comparing Java enum members: == or equals()?

I know that Java enums are compiled to classes with private constructors and a bunch of public static members. When comparing two members of a given enum, I've always used .equals(), e.g. public useEnums(SomeEnum a) { if(a.equals(…

Read More
Using Enum values as String literals

What is the best way to use the values stored in an Enum as String literals? For example: public enum Modes { some-really-long-string, mode1, mode2, mode3 } Then later I could use Mode.mode1 to return its string representation as mode1. Without …

Read More