Skip to content

Most visited

Recently visited

navigation

Enum

public abstract class Enum
extends Object implements Comparable<E extends Enum<E>>, Serializable

java.lang.Object
   ↳ java.lang.Enum<E extends java.lang.Enum<E>>
Known Direct Subclasses


This is the common base class of all Java language enumeration types. More information about enums, including descriptions of the implicitly declared methods synthesized by the compiler, can be found in section 8.9 of The Java™ Language Specification.

Note that when using an enumeration type as the type of a set or as the type of the keys in a map, specialized and efficient set and map implementations are available.

See also:

Summary

Protected constructors

Enum(String name, int ordinal)

Sole constructor.

Public methods

final int compareTo(E o)

Compares this enum with the specified object for order.

final boolean equals(Object other)

Returns true if the specified object is equal to this enum constant.

final Class<E> getDeclaringClass()

Returns the Class object corresponding to this enum constant's enum type.

final int hashCode()

Returns a hash code for this enum constant.

final String name()

Returns the name of this enum constant, exactly as declared in its enum declaration.

final int ordinal()

Returns the ordinal of this enumeration constant (its position in its enum declaration, where the initial constant is assigned an ordinal of zero).

String toString()

Returns the name of this enum constant, as contained in the declaration.

static <T extends Enum<T>> T valueOf(Class<T> enumType, String name)

Returns the enum constant of the specified enum type with the specified name.

Protected methods

final Object clone()

Throws CloneNotSupportedException.

final void finalize()

enum classes cannot have finalize methods.

Inherited methods

From class java.lang.Object
From interface java.lang.Comparable

Protected constructors

Enum

Added in API level 1
Enum (String name, 
                int ordinal)

Sole constructor. Programmers cannot invoke this constructor. It is for use by code emitted by the compiler in response to enum type declarations.

Parameters
name String: - The name of this enum constant, which is the identifier used to declare it.
ordinal int: - The ordinal of this enumeration constant (its position in the enum declaration, where the initial constant is assigned an ordinal of zero).

Public methods

compareTo

Added in API level 1
int compareTo (E o)

Compares this enum with the specified object for order. Returns a negative integer, zero, or a positive integer as this object is less than, equal to, or greater than the specified object. Enum constants are only comparable to other enum constants of the same enum type. The natural order implemented by this method is the order in which the constants are declared.

Parameters
o E
Returns
int

equals

Added in API level 1
boolean equals (Object other)

Returns true if the specified object is equal to this enum constant.

Parameters
other Object: the object to be compared for equality with this object.
Returns
boolean true if the specified object is equal to this enum constant.

getDeclaringClass

Added in API level 1
Class<E> getDeclaringClass ()

Returns the Class object corresponding to this enum constant's enum type. Two enum constants e1 and e2 are of the same enum type if and only if e1.getDeclaringClass() == e2.getDeclaringClass(). (The value returned by this method may differ from the one returned by the getClass() method for enum constants with constant-specific class bodies.)

Returns
Class<E> the Class object corresponding to this enum constant's enum type

hashCode

Added in API level 1
int hashCode ()

Returns a hash code for this enum constant.

Returns
int a hash code for this enum constant.

name

Added in API level 1
String name ()

Returns the name of this enum constant, exactly as declared in its enum declaration. Most programmers should use the toString() method in preference to this one, as the toString method may return a more user-friendly name. This method is designed primarily for use in specialized situations where correctness depends on getting the exact name, which will not vary from release to release.

Returns
String the name of this enum constant

ordinal

Added in API level 1
int ordinal ()

Returns the ordinal of this enumeration constant (its position in its enum declaration, where the initial constant is assigned an ordinal of zero). Most programmers will have no use for this method. It is designed for use by sophisticated enum-based data structures, such as EnumSet and EnumMap.

Returns
int the ordinal of this enumeration constant

toString

Added in API level 1
String toString ()

Returns the name of this enum constant, as contained in the declaration. This method may be overridden, though it typically isn't necessary or desirable. An enum type should override this method when a more "programmer-friendly" string form exists.

Returns
String the name of this enum constant

valueOf

Added in API level 1
T valueOf (Class<T> enumType, 
                String name)

Returns the enum constant of the specified enum type with the specified name. The name must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Note that for a particular enum type T, the implicitly declared public static T valueOf(String) method on that enum may be used instead of this method to map from a name to the corresponding enum constant. All the constants of an enum type can be obtained by calling the implicit public static T[] values() method of that type.

Parameters
enumType Class: the Class object of the enum type from which to return a constant
name String: the name of the constant to return
Returns
T the enum constant of the specified enum type with the specified name
Throws
IllegalArgumentException if the specified enum type has no constant with the specified name, or the specified class object does not represent an enum type
NullPointerException if enumType or name is null

Protected methods

clone

Added in API level 1
Object clone ()

Throws CloneNotSupportedException. This guarantees that enums are never cloned, which is necessary to preserve their "singleton" status.

Returns
Object (never returns)
Throws
CloneNotSupportedException

finalize

Added in API level 1
void finalize ()

enum classes cannot have finalize methods.

This site uses cookies to store your preferences for site-specific language and display options.

Hooray!

This class requires API level or higher

This doc is hidden because your selected API level for the documentation is . You can change the documentation API level with the selector above the left navigation.

For more information about specifying the API level your app requires, read Supporting Different Platform Versions.

Take a one-minute survey?
Help us improve Android tools and documentation.