IsoEra (Java SE 22 & JDK 22)
Description: declaration: module: java.base, package: java.time.chrono, enum: IsoEra
Keywords: java.time.chrono.IsoEra class

Module java.base
Package java.time.chrono

# Enum Class IsoEra

java.lang.Object
java.lang.Enum<IsoEra>
java.time.chrono.IsoEra

All Implemented Interfaces:
  `Serializable`, `Comparable<IsoEra>`, `Constable`, `Era`, `TemporalAccessor`, `TemporalAdjuster`

public enum IsoEra extends Enum<IsoEra> implements Era
An era in the ISO calendar system.

The ISO-8601 standard does not define eras. A definition has therefore been created with two eras - 'Current era' (CE) for years on or after 0001-01-01 (ISO), and 'Before current era' (BCE) for years before that.

ISO years and eras
year-of-era | era | proleptic-year
--- | --- | ---
2 | CE | 2
1 | CE | 1
1 | BCE | 0
2 | BCE | -1

Do not use `ordinal()` to obtain the numeric representation of `IsoEra`. Use `getValue()` instead.

Implementation Requirements:
  This is an immutable and thread-safe enum.
Since:
  1.8

- ## Nested Class Summary

  ### Nested classes/interfaces declared in class java.lang.Enum

  `Enum.EnumDesc<E extends Enum<E>>`

- ## Enum Constant Summary

  Enum Constants
  Enum Constant
  Description
  `BCE`
  The singleton instance for the era before the current one, 'Before Current Era', which has the numeric value 0.
  `CE`
  The singleton instance for the current era, 'Current Era', which has the numeric value 1.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `int`
  `getValue()`
  Gets the numeric era `int` value.
  `static IsoEra`
  `of(int isoEra)`
  Obtains an instance of `IsoEra` from an `int` value.
  `static IsoEra`
  `valueOf(String name)`
  Returns the enum constant of this class with the specified name.
  `static IsoEra[]`
  `values()`
  Returns an array containing the constants of this enum class, in the order they are declared.

  ### Methods declared in class java.lang.Enum

  `clone, compareTo, describeConstable, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf`

  ### Methods declared in class java.lang.Object

  `getClass, notify, notifyAll, wait, wait, wait`

  ### Methods declared in interface java.time.chrono.Era

  `adjustInto, get, getDisplayName, getLong, isSupported, query, range`

- ## Enum Constant Details

  - ### BCE

    public static final IsoEra BCE
    The singleton instance for the era before the current one, 'Before Current Era', which has the numeric value 0.

  - ### CE

    public static final IsoEra CE
    The singleton instance for the current era, 'Current Era', which has the numeric value 1.

- ## Method Details

  - ### values

    public static IsoEra[] values()
    Returns an array containing the constants of this enum class, in the order they are declared.
    Returns:
      an array containing the constants of this enum class, in the order they are declared

  - ### valueOf

    public static IsoEra valueOf(String name)
    Returns the enum constant of this class with the specified name. The string must match exactly an identifier used to declare an enum constant in this class. (Extraneous whitespace characters are not permitted.)
    Parameters:
      `name` - the name of the enum constant to be returned.
    Returns:
      the enum constant with the specified name
    Throws:
      `IllegalArgumentException` - if this enum class has no constant with the specified name
      `NullPointerException` - if the argument is null

  - ### of

    public static IsoEra of(int isoEra)
    Obtains an instance of `IsoEra` from an `int` value.

    `IsoEra` is an enum representing the ISO eras of BCE/CE. This factory allows the enum to be obtained from the `int` value.

    Parameters:
      `isoEra` - the BCE/CE value to represent, from 0 (BCE) to 1 (CE)
    Returns:
      the era singleton, not null
    Throws:
      `DateTimeException` - if the value is invalid

  - ### getValue

    public int getValue()
    Gets the numeric era `int` value.

    The era BCE has the value 0, while the era CE has the value 1.

    Specified by:
      `getValue` in interface `Era`
    Returns:
      the era value, from 0 (BCE) to 1 (CE)