Versions

[{“Name”:“Java SE 5”,“GroupName”:null},{“Name”:“Java SE 6”,“GroupName”:null},{“Name”:“Java SE 7”,“GroupName”:null},{“Name”:“Java SE 8”,“GroupName”:null},{“Name”:“Java SE 9 (Early Access)”,“GroupName”:null}]

Introduction

Java enums (declared using the enum keyword) are shorthand syntax for sizable quantities of constants of a single class.

Syntax

Remarks

Restrictions

Enums always extend [java.lang.Enum](<https://docs.oracle.com/javase/7/docs/api/java/lang/Enum.html>), so it is impossible for an enum to extend a class. However, they can implement many interfaces.

Tips & Tricks

Because of their specialized representation, there are more efficient maps and sets that can be used with enums as their keys. These will often run quicker than their non-specialized counterparts.