Character

AI-generated Key Takeaways

The Character class in Java is a wrapper for the primitive char type, providing methods for character manipulation and categorization.
It supports Unicode characters, including supplementary characters represented by surrogate pairs.
Methods handle character properties, case conversion, code point manipulation, and identifier validation.
Some methods have limitations with supplementary characters, recommending the use of String methods instead.
It provides constants for character categories and Unicode properties for character analysis.

public final class Character extends Object
implements Serializable Comparable<Character>

The Character class wraps a value of the primitive type char in an object. An object of type Character contains a single field whose type is char.

In addition, this class provides several methods for determining a character's category (lowercase letter, digit, etc.) and for converting characters from uppercase to lowercase and vice versa.

Character information is based on the Unicode Standard, version 6.2.0.

The methods and data of class Character are defined by the information in the UnicodeData file that is part of the Unicode Character Database maintained by the Unicode Consortium. This file specifies various properties including name and general category for every defined Unicode code point or character range.

The file and its description are available from the Unicode Consortium at:

http://www.unicode.org

Unicode Character Representations

The char data type (and therefore the value that a Character object encapsulates) are based on the original Unicode specification, which defined characters as fixed-width 16-bit entities. The Unicode Standard has since been changed to allow for characters whose representation requires more than 16 bits. The range of legal code points is now U+0000 to U+10FFFF, known as Unicode scalar value. (Refer to the definition of the U+n notation in the Unicode Standard.)

The set of characters from U+0000 to U+FFFF is sometimes referred to as the Basic Multilingual Plane (BMP). Characters whose code points are greater than U+FFFF are called supplementary characters. The Java platform uses the UTF-16 representation in char arrays and in the String and StringBuffer classes. In this representation, supplementary characters are represented as a pair of char values, the first from the high-surrogates range, (\uD800-\uDBFF), the second from the low-surrogates range (\uDC00-\uDFFF).

A char value, therefore, represents Basic Multilingual Plane (BMP) code points, including the surrogate code points, or code units of the UTF-16 encoding. An int value represents all Unicode code points, including supplementary code points. The lower (least significant) 21 bits of int are used to represent Unicode code points and the upper (most significant) 11 bits must be zero. Unless otherwise specified, the behavior with respect to supplementary characters and surrogate char values is as follows:

The methods that only accept a char value cannot support supplementary characters. They treat char values from the surrogate ranges as undefined characters. For example, Character.isLetter('\uD840') returns false, even though this specific value if followed by any low-surrogate value in a string would represent a letter.
The methods that accept an int value support all Unicode characters, including supplementary characters. For example, Character.isLetter(0x2F81A) returns true because the code point value represents a letter (a CJK ideograph).

In the Java SE API documentation, Unicode code point is used for character values in the range between U+0000 and U+10FFFF, and Unicode code unit is used for 16-bit char values that are code units of the UTF-16 encoding. For more information on Unicode terminology, refer to the Unicode Glossary.

Nested Class Summary

class	Character.Subset	Instances of this class represent particular subsets of the Unicode character set.
class	Character.UnicodeBlock	A family of character subsets representing the character blocks in the Unicode specification.
enum	Character.UnicodeScript	A family of character subsets representing the character scripts defined in the Unicode Standard Annex #24: Script Names.

Constant Summary

int	BYTES	The number of bytes used to represent a `char` value in unsigned binary form.
byte	COMBINING_SPACING_MARK	General category "Mc" in the Unicode specification.
byte	CONNECTOR_PUNCTUATION	General category "Pc" in the Unicode specification.
byte	CONTROL	General category "Cc" in the Unicode specification.
byte	CURRENCY_SYMBOL	General category "Sc" in the Unicode specification.
byte	DASH_PUNCTUATION	General category "Pd" in the Unicode specification.
byte	DECIMAL_DIGIT_NUMBER	General category "Nd" in the Unicode specification.
byte	DIRECTIONALITY_ARABIC_NUMBER	Weak bidirectional character type "AN" in the Unicode specification.
byte	DIRECTIONALITY_BOUNDARY_NEUTRAL	Weak bidirectional character type "BN" in the Unicode specification.
byte	DIRECTIONALITY_COMMON_NUMBER_SEPARATOR	Weak bidirectional character type "CS" in the Unicode specification.
byte	DIRECTIONALITY_EUROPEAN_NUMBER	Weak bidirectional character type "EN" in the Unicode specification.
byte	DIRECTIONALITY_EUROPEAN_NUMBER_SEPARATOR	Weak bidirectional character type "ES" in the Unicode specification.
byte	DIRECTIONALITY_EUROPEAN_NUMBER_TERMINATOR	Weak bidirectional character type "ET" in the Unicode specification.
byte	DIRECTIONALITY_LEFT_TO_RIGHT	Strong bidirectional character type "L" in the Unicode specification.
byte	DIRECTIONALITY_LEFT_TO_RIGHT_EMBEDDING	Strong bidirectional character type "LRE" in the Unicode specification.
byte	DIRECTIONALITY_LEFT_TO_RIGHT_OVERRIDE	Strong bidirectional character type "LRO" in the Unicode specification.
byte	DIRECTIONALITY_NONSPACING_MARK	Weak bidirectional character type "NSM" in the Unicode specification.
byte	DIRECTIONALITY_OTHER_NEUTRALS	Neutral bidirectional character type "ON" in the Unicode specification.
byte	DIRECTIONALITY_PARAGRAPH_SEPARATOR	Neutral bidirectional character type "B" in the Unicode specification.
byte	DIRECTIONALITY_POP_DIRECTIONAL_FORMAT	Weak bidirectional character type "PDF" in the Unicode specification.
byte	DIRECTIONALITY_RIGHT_TO_LEFT	Strong bidirectional character type "R" in the Unicode specification.
byte	DIRECTIONALITY_RIGHT_TO_LEFT_ARABIC	Strong bidirectional character type "AL" in the Unicode specification.
byte	DIRECTIONALITY_RIGHT_TO_LEFT_EMBEDDING	Strong bidirectional character type "RLE" in the Unicode specification.
byte	DIRECTIONALITY_RIGHT_TO_LEFT_OVERRIDE	Strong bidirectional character type "RLO" in the Unicode specification.
byte	DIRECTIONALITY_SEGMENT_SEPARATOR	Neutral bidirectional character type "S" in the Unicode specification.
byte	DIRECTIONALITY_UNDEFINED	Undefined bidirectional character type.
byte	DIRECTIONALITY_WHITESPACE	Neutral bidirectional character type "WS" in the Unicode specification.
byte	ENCLOSING_MARK	General category "Me" in the Unicode specification.
byte	END_PUNCTUATION	General category "Pe" in the Unicode specification.
byte	FINAL_QUOTE_PUNCTUATION	General category "Pf" in the Unicode specification.
byte	FORMAT	General category "Cf" in the Unicode specification.
byte	INITIAL_QUOTE_PUNCTUATION	General category "Pi" in the Unicode specification.
byte	LETTER_NUMBER	General category "Nl" in the Unicode specification.
byte	LINE_SEPARATOR	General category "Zl" in the Unicode specification.
byte	LOWERCASE_LETTER	General category "Ll" in the Unicode specification.
byte	MATH_SYMBOL	General category "Sm" in the Unicode specification.
int	MAX_CODE_POINT	The maximum value of a Unicode code point, constant `U+10FFFF`.
char	MAX_HIGH_SURROGATE	The maximum value of a Unicode high-surrogate code unit in the UTF-16 encoding, constant `'\uDBFF'`.
char	MAX_LOW_SURROGATE	The maximum value of a Unicode low-surrogate code unit in the UTF-16 encoding, constant `'\uDFFF'`.
int	MAX_RADIX	The maximum radix available for conversion to and from strings.
char	MAX_SURROGATE	The maximum value of a Unicode surrogate code unit in the UTF-16 encoding, constant `'\uDFFF'`.
char	MAX_VALUE	The constant value of this field is the largest value of type `char`, `'\uFFFF'`.
int	MIN_CODE_POINT	The minimum value of a Unicode code point, constant `U+0000`.
char	MIN_HIGH_SURROGATE	The minimum value of a Unicode high-surrogate code unit in the UTF-16 encoding, constant `'\uD800'`.
char	MIN_LOW_SURROGATE	The minimum value of a Unicode low-surrogate code unit in the UTF-16 encoding, constant `'\uDC00'`.
int	MIN_RADIX	The minimum radix available for conversion to and from strings.
int	MIN_SUPPLEMENTARY_CODE_POINT	The minimum value of a Unicode supplementary code point, constant `U+10000`.
char	MIN_SURROGATE	The minimum value of a Unicode surrogate code unit in the UTF-16 encoding, constant `'\uD800'`.
char	MIN_VALUE	The constant value of this field is the smallest value of type `char`, `'\u0000'`.
byte	MODIFIER_LETTER	General category "Lm" in the Unicode specification.
byte	MODIFIER_SYMBOL	General category "Sk" in the Unicode specification.
byte	NON_SPACING_MARK	General category "Mn" in the Unicode specification.
byte	OTHER_LETTER	General category "Lo" in the Unicode specification.
byte	OTHER_NUMBER	General category "No" in the Unicode specification.
byte	OTHER_PUNCTUATION	General category "Po" in the Unicode specification.
byte	OTHER_SYMBOL	General category "So" in the Unicode specification.
byte	PARAGRAPH_SEPARATOR	General category "Zp" in the Unicode specification.
byte	PRIVATE_USE	General category "Co" in the Unicode specification.
int	SIZE	The number of bits used to represent a `char` value in unsigned binary form, constant `16`.
byte	SPACE_SEPARATOR	General category "Zs" in the Unicode specification.
byte	START_PUNCTUATION	General category "Ps" in the Unicode specification.
byte	SURROGATE	General category "Cs" in the Unicode specification.
byte	TITLECASE_LETTER	General category "Lt" in the Unicode specification.
byte	UNASSIGNED	General category "Cn" in the Unicode specification.
byte	UPPERCASE_LETTER	General category "Lu" in the Unicode specification.

Field Summary

public static final Class<Character> TYPE The Class instance representing the primitive type char.

Public Constructor Summary

Character(char value)

Constructs a newly allocated Character object that represents the specified char value.

Public Method Summary

static int	charCount(int codePoint) Determines the number of `char` values needed to represent the specified character (Unicode code point).
char	charValue() Returns the value of this `Character` object.
static int	codePointAt(char[] a, int index, int limit) Returns the code point at the given index of the `char` array, where only array elements with `index` less than `limit` can be used.
static int	codePointAt(char[] a, int index) Returns the code point at the given index of the `char` array.
static int	codePointAt(CharSequence seq, int index) Returns the code point at the given index of the `CharSequence`.
static int	codePointBefore(char[] a, int index) Returns the code point preceding the given index of the `char` array.
static int	codePointBefore(CharSequence seq, int index) Returns the code point preceding the given index of the `CharSequence`.
static int	codePointBefore(char[] a, int index, int start) Returns the code point preceding the given index of the `char` array, where only array elements with `index` greater than or equal to `start` can be used.
static int	codePointCount(CharSequence seq, int beginIndex, int endIndex) Returns the number of Unicode code points in the text range of the specified char sequence.
static int	codePointCount(char[] a, int offset, int count) Returns the number of Unicode code points in a subarray of the `char` array argument.
static int	compare(char x, char y) Compares two `char` values numerically.
int	compareTo(Character anotherCharacter) Compares two `Character` objects numerically.
static int	digit(int codePoint, int radix) Returns the numeric value of the specified character (Unicode code point) in the specified radix.
static int	digit(char ch, int radix) Returns the numeric value of the character `ch` in the specified radix.
boolean	equals(Object obj) Compares this object against the specified object.
static char	forDigit(int digit, int radix) Determines the character representation for a specific digit in the specified radix.
static byte	getDirectionality(char ch) Returns the Unicode directionality property for the given character.
static byte	getDirectionality(int codePoint) Returns the Unicode directionality property for the given character (Unicode code point).
static String	getName(int codePoint) Returns the Unicode name of the specified character `codePoint`, or null if the code point is `unassigned`.
static int	getNumericValue(int codePoint) Returns the `int` value that the specified character (Unicode code point) represents.
static int	getNumericValue(char ch) Returns the `int` value that the specified Unicode character represents.
static int	getType(char ch) Returns a value indicating a character's general category.
static int	getType(int codePoint) Returns a value indicating a character's general category.
static int	hashCode(char value) Returns a hash code for a `char` value; compatible with `Character.hashCode()`.
int	hashCode() Returns a hash code for this `Character`; equal to the result of invoking `charValue()`.
static char	highSurrogate(int codePoint) Returns the leading surrogate (a high surrogate code unit) of the surrogate pair representing the specified supplementary character (Unicode code point) in the UTF-16 encoding.
static boolean	isAlphabetic(int codePoint) Determines if the specified character (Unicode code point) is an alphabet.
static boolean	isBmpCodePoint(int codePoint) Determines whether the specified character (Unicode code point) is in the Basic Multilingual Plane (BMP).
static boolean	isDefined(int codePoint) Determines if a character (Unicode code point) is defined in Unicode.
static boolean	isDefined(char ch) Determines if a character is defined in Unicode.
static boolean	isDigit(char ch) Determines if the specified character is a digit.
static boolean	isDigit(int codePoint) Determines if the specified character (Unicode code point) is a digit.
static boolean	isHighSurrogate(char ch) Determines if the given `char` value is a Unicode high-surrogate code unit (also known as leading-surrogate code unit).
static boolean	isISOControl(char ch) Determines if the specified character is an ISO control character.
static boolean	isISOControl(int codePoint) Determines if the referenced character (Unicode code point) is an ISO control character.
static boolean	isIdentifierIgnorable(char ch) Determines if the specified character should be regarded as an ignorable character in a Java identifier or a Unicode identifier.
static boolean	isIdentifierIgnorable(int codePoint) Determines if the specified character (Unicode code point) should be regarded as an ignorable character in a Java identifier or a Unicode identifier.
static boolean	isIdeographic(int codePoint) Determines if the specified character (Unicode code point) is a CJKV (Chinese, Japanese, Korean and Vietnamese) ideograph, as defined by the Unicode Standard.
static boolean	isJavaIdentifierPart(char ch) Determines if the specified character may be part of a Java identifier as other than the first character.
static boolean	isJavaIdentifierPart(int codePoint) Determines if the character (Unicode code point) may be part of a Java identifier as other than the first character.
static boolean	isJavaIdentifierStart(int codePoint) Determines if the character (Unicode code point) is permissible as the first character in a Java identifier.
static boolean	isJavaIdentifierStart(char ch) Determines if the specified character is permissible as the first character in a Java identifier.
static boolean	isJavaLetter(char ch) This method is deprecated. Replaced by isJavaIdentifierStart(char).
static boolean	isJavaLetterOrDigit(char ch) This method is deprecated. Replaced by isJavaIdentifierPart(char).
static boolean	isLetter(char ch) Determines if the specified character is a letter.
static boolean	isLetter(int codePoint) Determines if the specified character (Unicode code point) is a letter.
static boolean	isLetterOrDigit(char ch) Determines if the specified character is a letter or digit.
static boolean	isLetterOrDigit(int codePoint) Determines if the specified character (Unicode code point) is a letter or digit.
static boolean	isLowSurrogate(char ch) Determines if the given `char` value is a Unicode low-surrogate code unit (also known as trailing-surrogate code unit).
static boolean	isLowerCase(char ch) Determines if the specified character is a lowercase character.
static boolean	isLowerCase(int codePoint) Determines if the specified character (Unicode code point) is a lowercase character.
static boolean	isMirrored(int codePoint) Determines whether the specified character (Unicode code point) is mirrored according to the Unicode specification.
static boolean	isMirrored(char ch) Determines whether the character is mirrored according to the Unicode specification.
static boolean	isSpace(char ch) This method is deprecated. Replaced by isWhitespace(char).
static boolean	isSpaceChar(char ch) Determines if the specified character is a Unicode space character.
static boolean	isSpaceChar(int codePoint) Determines if the specified character (Unicode code point) is a Unicode space character.
static boolean	isSupplementaryCodePoint(int codePoint) Determines whether the specified character (Unicode code point) is in the supplementary character range.
static boolean	isSurrogate(char ch) Determines if the given `char` value is a Unicode surrogate code unit.
static boolean	isSurrogatePair(char high, char low) Determines whether the specified pair of `char` values is a valid Unicode surrogate pair.
static boolean	isTitleCase(int codePoint) Determines if the specified character (Unicode code point) is a titlecase character.
static boolean	isTitleCase(char ch) Determines if the specified character is a titlecase character.
static boolean	isUnicodeIdentifierPart(int codePoint) Determines if the specified character (Unicode code point) may be part of a Unicode identifier as other than the first character.
static boolean	isUnicodeIdentifierPart(char ch) Determines if the specified character may be part of a Unicode identifier as other than the first character.
static boolean	isUnicodeIdentifierStart(int codePoint) Determines if the specified character (Unicode code point) is permissible as the first character in a Unicode identifier.
static boolean	isUnicodeIdentifierStart(char ch) Determines if the specified character is permissible as the first character in a Unicode identifier.
static boolean	isUpperCase(char ch) Determines if the specified character is an uppercase character.
static boolean	isUpperCase(int codePoint) Determines if the specified character (Unicode code point) is an uppercase character.
static boolean	isValidCodePoint(int codePoint) Determines whether the specified code point is a valid Unicode code point value.
static boolean	isWhitespace(int codePoint) Determines if the specified character (Unicode code point) is white space according to Java.
static boolean	isWhitespace(char ch) Determines if the specified character is white space according to Java.
static char	lowSurrogate(int codePoint) Returns the trailing surrogate (a low surrogate code unit) of the surrogate pair representing the specified supplementary character (Unicode code point) in the UTF-16 encoding.
static int	offsetByCodePoints(CharSequence seq, int index, int codePointOffset) Returns the index within the given char sequence that is offset from the given `index` by `codePointOffset` code points.
static int	offsetByCodePoints(char[] a, int start, int count, int index, int codePointOffset) Returns the index within the given `char` subarray that is offset from the given `index` by `codePointOffset` code points.
static char	reverseBytes(char ch) Returns the value obtained by reversing the order of the bytes in the specified `char` value.
static int	toChars(int codePoint, char[] dst, int dstIndex) Converts the specified character (Unicode code point) to its UTF-16 representation.
static char[]	toChars(int codePoint) Converts the specified character (Unicode code point) to its UTF-16 representation stored in a `char` array.
static int	toCodePoint(char high, char low) Converts the specified surrogate pair to its supplementary code point value.
static int	toLowerCase(int codePoint) Converts the character (Unicode code point) argument to lowercase using case mapping information from the UnicodeData file.
static char	toLowerCase(char ch) Converts the character argument to lowercase using case mapping information from the UnicodeData file.
String	toString() Returns a `String` object representing this `Character`'s value.
static String	toString(char c) Returns a `String` object representing the specified `char`.
static char	toTitleCase(char ch) Converts the character argument to titlecase using case mapping information from the UnicodeData file.
static int	toTitleCase(int codePoint) Converts the character (Unicode code point) argument to titlecase using case mapping information from the UnicodeData file.
static char	toUpperCase(char ch) Converts the character argument to uppercase using case mapping information from the UnicodeData file.
static int	toUpperCase(int codePoint) Converts the character (Unicode code point) argument to uppercase using case mapping information from the UnicodeData file.
static Character	valueOf(char c) Returns a `Character` instance representing the specified `char` value.

Inherited Method Summary

From class java.lang.Object

Object	clone() Creates and returns a copy of this `Object`.
boolean	equals(Object obj) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of `Class` that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait(long timeout, int nanos) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.
final void	wait(long timeout) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.
final void	wait() Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object.

From interface java.lang.Comparable

abstract int

compareTo(Character o)

Compares this object with the specified object for order.

Constants

public static final int BYTES

The number of bytes used to represent a char value in unsigned binary form.

Constant Value: 2

public static final byte COMBINING_SPACING_MARK

General category "Mc" in the Unicode specification.

Constant Value: 8

public static final byte CONNECTOR_PUNCTUATION

General category "Pc" in the Unicode specification.

Constant Value: 23

public static final byte CONTROL

General category "Cc" in the Unicode specification.

Constant Value: 15

public static final byte CURRENCY_SYMBOL

General category "Sc" in the Unicode specification.

Constant Value: 26

public static final byte DASH_PUNCTUATION

General category "Pd" in the Unicode specification.

Constant Value: 20

public static final byte DECIMAL_DIGIT_NUMBER

General category "Nd" in the Unicode specification.

Constant Value: 9

public static final byte DIRECTIONALITY_ARABIC_NUMBER

Weak bidirectional character type "AN" in the Unicode specification.

Constant Value: 6

public static final byte DIRECTIONALITY_BOUNDARY_NEUTRAL

Weak bidirectional character type "BN" in the Unicode specification.

Constant Value: 9

public static final byte DIRECTIONALITY_COMMON_NUMBER_SEPARATOR

Weak bidirectional character type "CS" in the Unicode specification.

Constant Value: 7

public static final byte DIRECTIONALITY_EUROPEAN_NUMBER

Weak bidirectional character type "EN" in the Unicode specification.

Constant Value: 3

public static final byte DIRECTIONALITY_EUROPEAN_NUMBER_SEPARATOR

Weak bidirectional character type "ES" in the Unicode specification.

Constant Value: 4

public static final byte DIRECTIONALITY_EUROPEAN_NUMBER_TERMINATOR

Weak bidirectional character type "ET" in the Unicode specification.

Constant Value: 5

public static final byte DIRECTIONALITY_LEFT_TO_RIGHT

Strong bidirectional character type "L" in the Unicode specification.

Constant Value: 0

public static final byte DIRECTIONALITY_LEFT_TO_RIGHT_EMBEDDING

Strong bidirectional character type "LRE" in the Unicode specification.

Constant Value: 14

public static final byte DIRECTIONALITY_LEFT_TO_RIGHT_OVERRIDE

Strong bidirectional character type "LRO" in the Unicode specification.

Constant Value: 15

public static final byte DIRECTIONALITY_NONSPACING_MARK

Weak bidirectional character type "NSM" in the Unicode specification.

Constant Value: 8

public static final byte DIRECTIONALITY_OTHER_NEUTRALS

Neutral bidirectional character type "ON" in the Unicode specification.

Constant Value: 13

public static final byte DIRECTIONALITY_PARAGRAPH_SEPARATOR

Neutral bidirectional character type "B" in the Unicode specification.

Constant Value: 10

public static final byte DIRECTIONALITY_POP_DIRECTIONAL_FORMAT

Weak bidirectional character type "PDF" in the Unicode specification.

Constant Value: 18

public static final byte DIRECTIONALITY_RIGHT_TO_LEFT

Strong bidirectional character type "R" in the Unicode specification.

Constant Value: 1

public static final byte DIRECTIONALITY_RIGHT_TO_LEFT_ARABIC

Strong bidirectional character type "AL" in the Unicode specification.

Constant Value: 2

public static final byte DIRECTIONALITY_RIGHT_TO_LEFT_EMBEDDING

Strong bidirectional character type "RLE" in the Unicode specification.

Constant Value: 16

public static final byte DIRECTIONALITY_RIGHT_TO_LEFT_OVERRIDE

Strong bidirectional character type "RLO" in the Unicode specification.

Constant Value: 17

public static final byte DIRECTIONALITY_SEGMENT_SEPARATOR

Neutral bidirectional character type "S" in the Unicode specification.

Constant Value: 11

public static final byte DIRECTIONALITY_UNDEFINED

Undefined bidirectional character type. Undefined char values have undefined directionality in the Unicode specification.

Constant Value: -1

public static final byte DIRECTIONALITY_WHITESPACE

Neutral bidirectional character type "WS" in the Unicode specification.

Constant Value: 12

public static final byte ENCLOSING_MARK

General category "Me" in the Unicode specification.

Constant Value: 7

public static final byte END_PUNCTUATION

General category "Pe" in the Unicode specification.

Constant Value: 22

public static final byte FINAL_QUOTE_PUNCTUATION

General category "Pf" in the Unicode specification.

Constant Value: 30

public static final byte FORMAT

General category "Cf" in the Unicode specification.

Constant Value: 16

public static final byte INITIAL_QUOTE_PUNCTUATION

General category "Pi" in the Unicode specification.

Constant Value: 29

public static final byte LETTER_NUMBER

General category "Nl" in the Unicode specification.

Constant Value: 10

public static final byte LINE_SEPARATOR

General category "Zl" in the Unicode specification.

Constant Value: 13

public static final byte LOWERCASE_LETTER

General category "Ll" in the Unicode specification.

Constant Value: 2

public static final byte MATH_SYMBOL

General category "Sm" in the Unicode specification.

Constant Value: 25

public static final int MAX_CODE_POINT

The maximum value of a Unicode code point, constant U+10FFFF.

Constant Value: 1114111

public static final char MAX_HIGH_SURROGATE

The maximum value of a Unicode high-surrogate code unit in the UTF-16 encoding, constant '\uDBFF'. A high-surrogate is also known as a leading-surrogate.

Constant Value: 56319

public static final char MAX_LOW_SURROGATE

The maximum value of a Unicode low-surrogate code unit in the UTF-16 encoding, constant '\uDFFF'. A low-surrogate is also known as a trailing-surrogate.

Constant Value: 57343

public static final int MAX_RADIX

The maximum radix available for conversion to and from strings. The constant value of this field is the largest value permitted for the radix argument in radix-conversion methods such as the digit method, the forDigit method, and the toString method of class Integer.

public static final char MAX_SURROGATE

The maximum value of a Unicode surrogate code unit in the UTF-16 encoding, constant '\uDFFF'.

Constant Value: 57343

public static final char MAX_VALUE

The constant value of this field is the largest value of type char, '\uFFFF'.

Constant Value: 65535

public static final int MIN_CODE_POINT

The minimum value of a Unicode code point, constant U+0000.

Constant Value: 0

public static final char MIN_HIGH_SURROGATE

The minimum value of a Unicode high-surrogate code unit in the UTF-16 encoding, constant '\uD800'. A high-surrogate is also known as a leading-surrogate.

Constant Value: 55296

public static final char MIN_LOW_SURROGATE

The minimum value of a Unicode low-surrogate code unit in the UTF-16 encoding, constant '\uDC00'. A low-surrogate is also known as a trailing-surrogate.

Constant Value: 56320

public static final int MIN_RADIX

The minimum radix available for conversion to and from strings. The constant value of this field is the smallest value permitted for the radix argument in radix-conversion methods such as the digit method, the forDigit method, and the toString method of class Integer.

public static final int MIN_SUPPLEMENTARY_CODE_POINT

The minimum value of a Unicode supplementary code point, constant U+10000.

Constant Value: 65536

public static final char MIN_SURROGATE

The minimum value of a Unicode surrogate code unit in the UTF-16 encoding, constant '\uD800'.

Constant Value: 55296

public static final char MIN_VALUE

The constant value of this field is the smallest value of type char, '\u0000'.

Constant Value: 0

public static final byte MODIFIER_LETTER

General category "Lm" in the Unicode specification.

Constant Value: 4

public static final byte MODIFIER_SYMBOL

General category "Sk" in the Unicode specification.

Constant Value: 27

public static final byte NON_SPACING_MARK

General category "Mn" in the Unicode specification.

Constant Value: 6

public static final byte OTHER_LETTER

General category "Lo" in the Unicode specification.

Constant Value: 5

public static final byte OTHER_NUMBER

General category "No" in the Unicode specification.

Constant Value: 11

public static final byte OTHER_PUNCTUATION

General category "Po" in the Unicode specification.

Constant Value: 24

public static final byte OTHER_SYMBOL

General category "So" in the Unicode specification.

Constant Value: 28

public static final byte PARAGRAPH_SEPARATOR

General category "Zp" in the Unicode specification.

Constant Value: 14

public static final byte PRIVATE_USE

General category "Co" in the Unicode specification.

Constant Value: 18

public static final int SIZE

The number of bits used to represent a char value in unsigned binary form, constant 16.

Constant Value: 16

public static final byte SPACE_SEPARATOR

General category "Zs" in the Unicode specification.

Constant Value: 12

public static final byte START_PUNCTUATION

General category "Ps" in the Unicode specification.

Constant Value: 21

public static final byte SURROGATE

General category "Cs" in the Unicode specification.

Constant Value: 19

public static final byte TITLECASE_LETTER

General category "Lt" in the Unicode specification.

Constant Value: 3

public static final byte UNASSIGNED

General category "Cn" in the Unicode specification.

Constant Value: 0

public static final byte UPPERCASE_LETTER

General category "Lu" in the Unicode specification.

Constant Value: 1

Fields

public static final Class<Character> TYPE

The Class instance representing the primitive type char.

Public Constructors

public Character (char value)

Constructs a newly allocated Character object that represents the specified char value.

Parameters

value	the value to be represented by the `Character` object.

Public Methods

public static int charCount (int codePoint)

Determines the number of char values needed to represent the specified character (Unicode code point). If the specified character is equal to or greater than 0x10000, then the method returns 2. Otherwise, the method returns 1.

This method doesn't validate the specified character to be a valid Unicode code point. The caller must validate the character value using isValidCodePoint if necessary.

Parameters

codePoint	the character (Unicode code point) to be tested.

Returns

2 if the character is a valid supplementary character; 1 otherwise.

public char charValue ()

Returns the value of this Character object.

Returns

the primitive char value represented by this object.

public static int codePointAt (char[] a, int index, int limit)

Returns the code point at the given index of the char array, where only array elements with index less than limit can be used. If the char value at the given index in the char array is in the high-surrogate range, the following index is less than the limit, and the char value at the following index is in the low-surrogate range, then the supplementary code point corresponding to this surrogate pair is returned. Otherwise, the char value at the given index is returned.

Parameters

a	the `char` array
index	the index to the `char` values (Unicode code units) in the `char` array to be converted
limit	the index after the last array element that can be used in the `char` array

Returns

the Unicode code point at the given index

Throws

NullPointerException	if `a` is null.
IndexOutOfBoundsException	if the `index` argument is negative or not less than the `limit` argument, or if the `limit` argument is negative or greater than the length of the `char` array.

public static int codePointAt (char[] a, int index)

Returns the code point at the given index of the char array. If the char value at the given index in the char array is in the high-surrogate range, the following index is less than the length of the char array, and the char value at the following index is in the low-surrogate range, then the supplementary code point corresponding to this surrogate pair is returned. Otherwise, the char value at the given index is returned.

Parameters

a	the `char` array
index	the index to the `char` values (Unicode code units) in the `char` array to be converted

Returns

the Unicode code point at the given index

Throws

NullPointerException	if `a` is null.
IndexOutOfBoundsException	if the value `index` is negative or not less than the length of the `char` array.

public static int codePointAt (CharSequence seq, int index)

Returns the code point at the given index of the CharSequence. If the char value at the given index in the CharSequence is in the high-surrogate range, the following index is less than the length of the CharSequence, and the char value at the following index is in the low-surrogate range, then the supplementary code point corresponding to this surrogate pair is returned. Otherwise, the char value at the given index is returned.

Parameters

seq	a sequence of `char` values (Unicode code units)
index	the index to the `char` values (Unicode code units) in `seq` to be converted

Returns

the Unicode code point at the given index

Throws

NullPointerException	if `seq` is null.
IndexOutOfBoundsException	if the value `index` is negative or not less than `seq.length()`.

public static int codePointBefore (char[] a, int index)

Returns the code point preceding the given index of the char array. If the char value at (index - 1) in the char array is in the low-surrogate range, (index - 2) is not negative, and the char value at (index - 2) in the char array is in the high-surrogate range, then the supplementary code point corresponding to this surrogate pair is returned. Otherwise, the char value at (index - 1) is returned.

Parameters

a	the `char` array
index	the index following the code point that should be returned

Returns

the Unicode code point value before the given index.

Throws

NullPointerException	if `a` is null.
IndexOutOfBoundsException	if the `index` argument is less than 1 or greater than the length of the `char` array

public static int codePointBefore (CharSequence seq, int index)

Returns the code point preceding the given index of the CharSequence. If the char value at (index - 1) in the CharSequence is in the low-surrogate range, (index - 2) is not negative, and the char value at (index - 2) in the CharSequence is in the high-surrogate range, then the supplementary code point corresponding to this surrogate pair is returned. Otherwise, the char value at (index - 1) is returned.

Parameters

seq	the `CharSequence` instance
index	the index following the code point that should be returned

Returns

the Unicode code point value before the given index.

Throws

NullPointerException	if `seq` is null.
IndexOutOfBoundsException	if the `index` argument is less than 1 or greater than `seq.length()`.

public static int codePointBefore (char[] a, int index, int start)

Returns the code point preceding the given index of the char array, where only array elements with index greater than or equal to start can be used. If the char value at (index - 1) in the char array is in the low-surrogate range, (index - 2) is not less than start, and the char value at (index - 2) in the char array is in the high-surrogate range, then the supplementary code point corresponding to this surrogate pair is returned. Otherwise, the char value at (index - 1) is returned.

Parameters

a	the `char` array
index	the index following the code point that should be returned
start	the index of the first array element in the `char` array

Returns

the Unicode code point value before the given index.

Throws

NullPointerException	if `a` is null.
IndexOutOfBoundsException	if the `index` argument is not greater than the `start` argument or is greater than the length of the `char` array, or if the `start` argument is negative or not less than the length of the `char` array.

public static int codePointCount (CharSequence seq, int beginIndex, int endIndex)

Returns the number of Unicode code points in the text range of the specified char sequence. The text range begins at the specified beginIndex and extends to the char at index endIndex - 1. Thus the length (in chars) of the text range is endIndex-beginIndex. Unpaired surrogates within the text range count as one code point each.

Parameters

seq	the char sequence
beginIndex	the index to the first `char` of the text range.
endIndex	the index after the last `char` of the text range.

Returns

the number of Unicode code points in the specified text range

Throws

NullPointerException	if `seq` is null.
IndexOutOfBoundsException	if the `beginIndex` is negative, or `endIndex` is larger than the length of the given sequence, or `beginIndex` is larger than `endIndex`.

public static int codePointCount (char[] a, int offset, int count)

Returns the number of Unicode code points in a subarray of the char array argument. The offset argument is the index of the first char of the subarray and the count argument specifies the length of the subarray in chars. Unpaired surrogates within the subarray count as one code point each.

Parameters

a	the `char` array
offset	the index of the first `char` in the given `char` array
count	the length of the subarray in `char`s

Returns

the number of Unicode code points in the specified subarray

Throws

NullPointerException	if `a` is null.
IndexOutOfBoundsException	if `offset` or `count` is negative, or if `offset + count` is larger than the length of the given array.

public static int compare (char x, char y)

Compares two char values numerically. The value returned is identical to what would be returned by:

    Character.valueOf(x).compareTo(Character.valueOf(y))

Parameters

x	the first `char` to compare
y	the second `char` to compare

Returns

the value 0 if x == y; a value less than 0 if x < y; and a value greater than 0 if x > y

public int compareTo (Character anotherCharacter)

Compares two Character objects numerically.

Parameters

anotherCharacter	the `Character` to be compared.

Returns

the value 0 if the argument Character is equal to this Character; a value less than 0 if this Character is numerically less than the Character argument; and a value greater than 0 if this Character is numerically greater than the Character argument (unsigned comparison). Note that this is strictly a numerical comparison; it is not locale-dependent.

public static int digit (int codePoint, int radix)

Returns the numeric value of the specified character (Unicode code point) in the specified radix.

If the radix is not in the range MIN_RADIX ≤ radix ≤ MAX_RADIX or if the character is not a valid digit in the specified radix, -1 is returned. A character is a valid digit if at least one of the following is true:

The method isDigit(codePoint) is true of the character and the Unicode decimal digit value of the character (or its single-character decomposition) is less than the specified radix. In this case the decimal digit value is returned.
The character is one of the uppercase Latin letters 'A' through 'Z' and its code is less than radix + 'A' - 10. In this case, codePoint - 'A' + 10 is returned.
The character is one of the lowercase Latin letters 'a' through 'z' and its code is less than radix + 'a' - 10. In this case, codePoint - 'a' + 10 is returned.
The character is one of the fullwidth uppercase Latin letters A ('\uFF21') through Z ('\uFF3A') and its code is less than radix + '\uFF21' - 10. In this case, codePoint - '\uFF21' + 10 is returned.
The character is one of the fullwidth lowercase Latin letters a ('\uFF41') through z ('\uFF5A') and its code is less than radix + '\uFF41'- 10. In this case, codePoint - '\uFF41' + 10 is returned.

Parameters

codePoint	the character (Unicode code point) to be converted.
radix	the radix.

Returns

the numeric value represented by the character in the specified radix.

public static int digit (char ch, int radix)

Returns the numeric value of the character ch in the specified radix.

If the radix is not in the range MIN_RADIX ≤ radix ≤ MAX_RADIX or if the value of ch is not a valid digit in the specified radix, -1 is returned. A character is a valid digit if at least one of the following is true:

The method isDigit is true of the character and the Unicode decimal digit value of the character (or its single-character decomposition) is less than the specified radix. In this case the decimal digit value is returned.
The character is one of the uppercase Latin letters 'A' through 'Z' and its code is less than radix + 'A' - 10. In this case, ch - 'A' + 10 is returned.
The character is one of the lowercase Latin letters 'a' through 'z' and its code is less than radix + 'a' - 10. In this case, ch - 'a' + 10 is returned.
The character is one of the fullwidth uppercase Latin letters A ('\uFF21') through Z ('\uFF3A') and its code is less than radix + '\uFF21' - 10. In this case, ch - '\uFF21' + 10 is returned.
The character is one of the fullwidth lowercase Latin letters a ('\uFF41') through z ('\uFF5A') and its code is less than radix + '\uFF41' - 10. In this case, ch - '\uFF41' + 10 is returned.

Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the digit(int, int) method.

Parameters

ch	the character to be converted.
radix	the radix.

Returns

the numeric value represented by the character in the specified radix.

public boolean equals (Object obj)

Compares this object against the specified object. The result is true if and only if the argument is not null and is a Character object that represents the same char value as this object.

Parameters

obj	the object to compare with.

Returns

true if the objects are the same; false otherwise.

public static char forDigit (int digit, int radix)

Determines the character representation for a specific digit in the specified radix. If the value of radix is not a valid radix, or the value of digit is not a valid digit in the specified radix, the null character ('\u0000') is returned.

The radix argument is valid if it is greater than or equal to MIN_RADIX and less than or equal to MAX_RADIX. The digit argument is valid if 0 <= digit < radix.

If the digit is less than 10, then '0' + digit is returned. Otherwise, the value 'a' + digit - 10 is returned.

Parameters

digit	the number to convert to a character.
radix	the radix.

Returns

the char representation of the specified digit in the specified radix.

public static byte getDirectionality (char ch)

Returns the Unicode directionality property for the given character. Character directionality is used to calculate the visual ordering of text. The directionality value of undefined char values is DIRECTIONALITY_UNDEFINED.

Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the getDirectionality(int) method.

Parameters

ch	`char` for which the directionality property is requested.

Returns

the directionality property of the char value.

public static byte getDirectionality (int codePoint)

Returns the Unicode directionality property for the given character (Unicode code point). Character directionality is used to calculate the visual ordering of text. The directionality value of undefined character is DIRECTIONALITY_UNDEFINED.

Parameters

codePoint	the character (Unicode code point) for which the directionality property is requested.

Returns

the directionality property of the character.

public static String getName (int codePoint)

Returns the Unicode name of the specified character codePoint, or null if the code point is unassigned.

Note: if the specified character is not assigned a name by the UnicodeData file (part of the Unicode Character Database maintained by the Unicode Consortium), the returned name is the same as the result of expression.

Character.UnicodeBlock.of(codePoint).toString().replace('_', ' ') + " " + Integer.toHexString(codePoint).toUpperCase(Locale.ENGLISH);

Parameters

codePoint	the character (Unicode code point)

Returns

the Unicode name of the specified character, or null if the code point is unassigned.

Throws

IllegalArgumentException	if the specified `codePoint` is not a valid Unicode code point.

public static int getNumericValue (int codePoint)

Returns the int value that the specified character (Unicode code point) represents. For example, the character '\u216C' (the Roman numeral fifty) will return an int with a value of 50.

The letters A-Z in their uppercase ('\u0041' through '\u005A'), lowercase ('\u0061' through '\u007A'), and full width variant ('\uFF21' through '\uFF3A' and '\uFF41' through '\uFF5A') forms have numeric values from 10 through 35. This is independent of the Unicode specification, which does not assign numeric values to these char values.

If the character does not have a numeric value, then -1 is returned. If the character has a numeric value that cannot be represented as a nonnegative integer (for example, a fractional value), then -2 is returned.

Parameters

codePoint	the character (Unicode code point) to be converted.

Returns

the numeric value of the character, as a nonnegative int value; -2 if the character has a numeric value that is not a nonnegative integer; -1 if the character has no numeric value.

public static int getNumericValue (char ch)

Returns the int value that the specified Unicode character represents. For example, the character '\u216C' (the roman numeral fifty) will return an int with a value of 50.

Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the getNumericValue(int) method.

Parameters

ch	the character to be converted.

Returns

the numeric value of the character, as a nonnegative int value; -2 if the character has a numeric value that is not a nonnegative integer; -1 if the character has no numeric value.

public static int getType (char ch)

Returns a value indicating a character's general category.

Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the getType(int) method.

Parameters

ch	the character to be tested.

Returns

a value of type int representing the character's general category.

public static int getType (int codePoint)

Returns a value indicating a character's general category.

Parameters

codePoint	the character (Unicode code point) to be tested.

Returns

a value of type int representing the character's general category.

public static int hashCode (char value)

Returns a hash code for a char value; compatible with Character.hashCode().

Parameters

value	The `char` for which to return a hash code.

Returns

a hash code value for a char value.

public int hashCode ()

Returns a hash code for this Character; equal to the result of invoking charValue().

Returns

a hash code value for this Character

public static char highSurrogate (int codePoint)

Returns the leading surrogate (a high surrogate code unit) of the surrogate pair representing the specified supplementary character (Unicode code point) in the UTF-16 encoding. If the specified character is not a supplementary character, an unspecified char is returned.

If isSupplementaryCodePoint(x) is true, then isHighSurrogate(highSurrogate(x)) and toCodePoint(highSurrogate(x), lowSurrogate(x)) == x are also always true.

Parameters

codePoint	a supplementary character (Unicode code point)

Returns

the leading surrogate code unit used to represent the character in the UTF-16 encoding

public static boolean isAlphabetic (int codePoint)

Determines if the specified character (Unicode code point) is an alphabet.

A character is considered to be alphabetic if its general category type, provided by getType(codePoint), is any of the following:

UPPERCASE_LETTER
LOWERCASE_LETTER
TITLECASE_LETTER
MODIFIER_LETTER
OTHER_LETTER
LETTER_NUMBER

or it has contributory property Other_Alphabetic as defined by the Unicode Standard.

Parameters

codePoint	the character (Unicode code point) to be tested.

Returns

true if the character is a Unicode alphabet character, false otherwise.

public static boolean isBmpCodePoint (int codePoint)

Determines whether the specified character (Unicode code point) is in the Basic Multilingual Plane (BMP). Such code points can be represented using a single char.

Parameters

codePoint	the character (Unicode code point) to be tested

Returns

true if the specified code point is between MIN_VALUE and MAX_VALUE inclusive; false otherwise.

public static boolean isDefined (int codePoint)

Determines if a character (Unicode code point) is defined in Unicode.

A character is defined if at least one of the following is true:

It has an entry in the UnicodeData file.
It has a value in a range defined by the UnicodeData file.

Parameters

codePoint	the character (Unicode code point) to be tested.

Returns

true if the character has a defined meaning in Unicode; false otherwise.

public static boolean isDefined (char ch)

Determines if a character is defined in Unicode.

A character is defined if at least one of the following is true:

It has an entry in the UnicodeData file.
It has a value in a range defined by the UnicodeData file.

Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isDefined(int) method.

Parameters

ch	the character to be tested

Returns

true if the character has a defined meaning in Unicode; false otherwise.

public static boolean isDigit (char ch)

Determines if the specified character is a digit.

A character is a digit if its general category type, provided by Character.getType(ch), is DECIMAL_DIGIT_NUMBER.

Some Unicode character ranges that contain digits:

'\u0030' through '\u0039', ISO-LATIN-1 digits ('0' through '9')
'\u0660' through '\u0669', Arabic-Indic digits
'\u06F0' through '\u06F9', Extended Arabic-Indic digits
'\u0966' through '\u096F', Devanagari digits
'\uFF10' through '\uFF19', Fullwidth digits

Many other character ranges contain digits as well.

Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isDigit(int) method.

Parameters

ch	the character to be tested.

Returns

true if the character is a digit; false otherwise.

public static boolean isDigit (int codePoint)

Determines if the specified character (Unicode code point) is a digit.

A character is a digit if its general category type, provided by getType(codePoint), is DECIMAL_DIGIT_NUMBER.

Some Unicode character ranges that contain digits:

'\u0030' through '\u0039', ISO-LATIN-1 digits ('0' through '9')
'\u0660' through '\u0669', Arabic-Indic digits
'\u06F0' through '\u06F9', Extended Arabic-Indic digits
'\u0966' through '\u096F', Devanagari digits
'\uFF10' through '\uFF19', Fullwidth digits

Many other character ranges contain digits as well.

Parameters

codePoint	the character (Unicode code point) to be tested.

Returns

true if the character is a digit; false otherwise.

public static boolean isHighSurrogate (char ch)

Determines if the given char value is a Unicode high-surrogate code unit (also known as leading-surrogate code unit).

Such values do not represent characters by themselves, but are used in the representation of supplementary characters in the UTF-16 encoding.

Parameters

ch	the `char` value to be tested.

Returns

true if the char value is between MIN_HIGH_SURROGATE and MAX_HIGH_SURROGATE inclusive; false otherwise.

public static boolean isISOControl (char ch)

Determines if the specified character is an ISO control character. A character is considered to be an ISO control character if its code is in the range '\u0000' through '\u001F' or in the range '\u007F' through '\u009F'.

Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isISOControl(int) method.

Parameters

ch	the character to be tested.

Returns

true if the character is an ISO control character; false otherwise.

public static boolean isISOControl (int codePoint)

Determines if the referenced character (Unicode code point) is an ISO control character. A character is considered to be an ISO control character if its code is in the range '\u0000' through '\u001F' or in the range '\u007F' through '\u009F'.

Parameters

codePoint	the character (Unicode code point) to be tested.

Returns

true if the character is an ISO control character; false otherwise.

public static boolean isIdentifierIgnorable (char ch)

Determines if the specified character should be regarded as an ignorable character in a Java identifier or a Unicode identifier.

The following Unicode characters are ignorable in a Java identifier or a Unicode identifier:

ISO control characters that are not whitespace
- '\u0000' through '\u0008'
- '\u000E' through '\u001B'
- '\u007F' through '\u009F'
all characters that have the FORMAT general category value

Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isIdentifierIgnorable(int) method.

Parameters

ch	the character to be tested.

Returns

true if the character is an ignorable control character that may be part of a Java or Unicode identifier; false otherwise.

public static boolean isIdentifierIgnorable (int codePoint)

Determines if the specified character (Unicode code point) should be regarded as an ignorable character in a Java identifier or a Unicode identifier.

The following Unicode characters are ignorable in a Java identifier or a Unicode identifier:

ISO control characters that are not whitespace
- '\u0000' through '\u0008'
- '\u000E' through '\u001B'
- '\u007F' through '\u009F'
all characters that have the FORMAT general category value

Parameters

codePoint	the character (Unicode code point) to be tested.

Returns

true if the character is an ignorable control character that may be part of a Java or Unicode identifier; false otherwise.

public static boolean isIdeographic (int codePoint)

Determines if the specified character (Unicode code point) is a CJKV (Chinese, Japanese, Korean and Vietnamese) ideograph, as defined by the Unicode Standard.

Parameters

codePoint	the character (Unicode code point) to be tested.

Returns

true if the character is a Unicode ideograph character, false otherwise.

public static boolean isJavaIdentifierPart (char ch)

Determines if the specified character may be part of a Java identifier as other than the first character.

A character may be part of a Java identifier if any of the following are true:

it is a letter
it is a currency symbol (such as '$')
it is a connecting punctuation character (such as '_')
it is a digit
it is a numeric letter (such as a Roman numeral character)
it is a combining mark
it is a non-spacing mark
isIdentifierIgnorable returns true for the character

Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isJavaIdentifierPart(int) method.

Parameters

ch	the character to be tested.

Returns

true if the character may be part of a Java identifier; false otherwise.

public static boolean isJavaIdentifierPart (int codePoint)

Determines if the character (Unicode code point) may be part of a Java identifier as other than the first character.

A character may be part of a Java identifier if any of the following are true:

it is a letter
it is a currency symbol (such as '$')
it is a connecting punctuation character (such as '_')
it is a digit
it is a numeric letter (such as a Roman numeral character)
it is a combining mark
it is a non-spacing mark
isIdentifierIgnorable(codePoint) returns true for the character

Parameters

codePoint	the character (Unicode code point) to be tested.

Returns

true if the character may be part of a Java identifier; false otherwise.

public static boolean isJavaIdentifierStart (int codePoint)

Determines if the character (Unicode code point) is permissible as the first character in a Java identifier.

A character may start a Java identifier if and only if one of the following conditions is true:

isLetter(codePoint) returns true
getType(codePoint) returns LETTER_NUMBER
the referenced character is a currency symbol (such as '$')
the referenced character is a connecting punctuation character (such as '_').

Parameters

codePoint	the character (Unicode code point) to be tested.

Returns

true if the character may start a Java identifier; false otherwise.

public static boolean isJavaIdentifierStart (char ch)

Determines if the specified character is permissible as the first character in a Java identifier.

A character may start a Java identifier if and only if one of the following conditions is true:

isLetter(ch) returns true
getType(ch) returns LETTER_NUMBER
ch is a currency symbol (such as '$')
ch is a connecting punctuation character (such as '_').

Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isJavaIdentifierStart(int) method.

Parameters

ch	the character to be tested.

Returns

true if the character may start a Java identifier; false otherwise.

public static boolean isJavaLetter (char ch)

This method is deprecated.
Replaced by isJavaIdentifierStart(char).

Determines if the specified character is permissible as the first character in a Java identifier.

A character may start a Java identifier if and only if one of the following is true:

isLetter(ch) returns true
getType(ch) returns LETTER_NUMBER
ch is a currency symbol (such as '$')
ch is a connecting punctuation character (such as '_').

Parameters

ch	the character to be tested.

Returns

true if the character may start a Java identifier; false otherwise.

public static boolean isJavaLetterOrDigit (char ch)

This method is deprecated.
Replaced by isJavaIdentifierPart(char).

Determines if the specified character may be part of a Java identifier as other than the first character.

A character may be part of a Java identifier if and only if any of the following are true:

it is a letter
it is a currency symbol (such as '$')
it is a connecting punctuation character (such as '_')
it is a digit
it is a numeric letter (such as a Roman numeral character)
it is a combining mark
it is a non-spacing mark
isIdentifierIgnorable returns true for the character.

Parameters

ch	the character to be tested.

Returns

true if the character may be part of a Java identifier; false otherwise.

public static boolean isLetter (char ch)

Determines if the specified character is a letter.

A character is considered to be a letter if its general category type, provided by Character.getType(ch), is any of the following:

UPPERCASE_LETTER
LOWERCASE_LETTER
TITLECASE_LETTER
MODIFIER_LETTER
OTHER_LETTER

Not all letters have case. Many characters are letters but are neither uppercase nor lowercase nor titlecase.

Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isLetter(int) method.

Parameters

ch	the character to be tested.

Returns

true if the character is a letter; false otherwise.

public static boolean isLetter (int codePoint)

Determines if the specified character (Unicode code point) is a letter.

A character is considered to be a letter if its general category type, provided by getType(codePoint), is any of the following:

UPPERCASE_LETTER
LOWERCASE_LETTER
TITLECASE_LETTER
MODIFIER_LETTER
OTHER_LETTER

Not all letters have case. Many characters are letters but are neither uppercase nor lowercase nor titlecase.

Parameters

codePoint	the character (Unicode code point) to be tested.

Returns

true if the character is a letter; false otherwise.

public static boolean isLetterOrDigit (char ch)

Determines if the specified character is a letter or digit.

A character is considered to be a letter or digit if either Character.isLetter(char ch) or Character.isDigit(char ch) returns true for the character.

Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isLetterOrDigit(int) method.

Parameters

ch	the character to be tested.

Returns

true if the character is a letter or digit; false otherwise.

public static boolean isLetterOrDigit (int codePoint)

Determines if the specified character (Unicode code point) is a letter or digit.

A character is considered to be a letter or digit if either isLetter(codePoint) or isDigit(codePoint) returns true for the character.

Parameters

codePoint	the character (Unicode code point) to be tested.

Returns

true if the character is a letter or digit; false otherwise.

public static boolean isLowSurrogate (char ch)

Determines if the given char value is a Unicode low-surrogate code unit (also known as trailing-surrogate code unit).

Such values do not represent characters by themselves, but are used in the representation of supplementary characters in the UTF-16 encoding.

Parameters

ch	the `char` value to be tested.

Returns

true if the char value is between MIN_LOW_SURROGATE and MAX_LOW_SURROGATE inclusive; false otherwise.

public static boolean isLowerCase (char ch)

Determines if the specified character is a lowercase character.

A character is lowercase if its general category type, provided by Character.getType(ch), is LOWERCASE_LETTER, or it has contributory property Other_Lowercase as defined by the Unicode Standard.

The following are examples of lowercase characters:

 a b c d e f g h i j k l m n o p q r s t u v w x y z
 '\u00DF' '\u00E0' '\u00E1' '\u00E2' '\u00E3' '\u00E4' '\u00E5' '\u00E6'
 '\u00E7' '\u00E8' '\u00E9' '\u00EA' '\u00EB' '\u00EC' '\u00ED' '\u00EE'
 '\u00EF' '\u00F0' '\u00F1' '\u00F2' '\u00F3' '\u00F4' '\u00F5' '\u00F6'
 '\u00F8' '\u00F9' '\u00FA' '\u00FB' '\u00FC' '\u00FD' '\u00FE' '\u00FF'

Many other Unicode characters are lowercase too.

Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isLowerCase(int) method.

Parameters

ch	the character to be tested.

Returns

true if the character is lowercase; false otherwise.

public static boolean isLowerCase (int codePoint)

Determines if the specified character (Unicode code point) is a lowercase character.

A character is lowercase if its general category type, provided by getType(codePoint), is LOWERCASE_LETTER, or it has contributory property Other_Lowercase as defined by the Unicode Standard.

The following are examples of lowercase characters:

 a b c d e f g h i j k l m n o p q r s t u v w x y z
 '\u00DF' '\u00E0' '\u00E1' '\u00E2' '\u00E3' '\u00E4' '\u00E5' '\u00E6'
 '\u00E7' '\u00E8' '\u00E9' '\u00EA' '\u00EB' '\u00EC' '\u00ED' '\u00EE'
 '\u00EF' '\u00F0' '\u00F1' '\u00F2' '\u00F3' '\u00F4' '\u00F5' '\u00F6'
 '\u00F8' '\u00F9' '\u00FA' '\u00FB' '\u00FC' '\u00FD' '\u00FE' '\u00FF'

Many other Unicode characters are lowercase too.

Parameters

codePoint	the character (Unicode code point) to be tested.

Returns

true if the character is lowercase; false otherwise.

public static boolean isMirrored (int codePoint)

Determines whether the specified character (Unicode code point) is mirrored according to the Unicode specification. Mirrored characters should have their glyphs horizontally mirrored when displayed in text that is right-to-left. For example, '\u0028' LEFT PARENTHESIS is semantically defined to be an opening parenthesis. This will appear as a "(" in text that is left-to-right but as a ")" in text that is right-to-left.

Parameters

codePoint	the character (Unicode code point) to be tested.

Returns

true if the character is mirrored, false if the character is not mirrored or is not defined.

public static boolean isMirrored (char ch)

Determines whether the character is mirrored according to the Unicode specification. Mirrored characters should have their glyphs horizontally mirrored when displayed in text that is right-to-left. For example, '\u0028' LEFT PARENTHESIS is semantically defined to be an opening parenthesis. This will appear as a "(" in text that is left-to-right but as a ")" in text that is right-to-left.

Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isMirrored(int) method.

Parameters

ch	`char` for which the mirrored property is requested

Returns

true if the char is mirrored, false if the char is not mirrored or is not defined.

public static boolean isSpace (char ch)

This method is deprecated.
Replaced by isWhitespace(char).

Determines if the specified character is ISO-LATIN-1 white space. This method returns true for the following five characters only:

`'\t'`	`U+0009`	`HORIZONTAL TABULATION`
`'\n'`	`U+000A`	`NEW LINE`
`'\f'`	`U+000C`	`FORM FEED`
`'\r'`	`U+000D`	`CARRIAGE RETURN`
`' '`	`U+0020`	`SPACE`

Parameters

ch	the character to be tested.

Returns

true if the character is ISO-LATIN-1 white space; false otherwise.

public static boolean isSpaceChar (char ch)

Determines if the specified character is a Unicode space character. A character is considered to be a space character if and only if it is specified to be a space character by the Unicode Standard. This method returns true if the character's general category type is any of the following:

SPACE_SEPARATOR
LINE_SEPARATOR
PARAGRAPH_SEPARATOR

Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isSpaceChar(int) method.

Parameters

ch	the character to be tested.

Returns

true if the character is a space character; false otherwise.

public static boolean isSpaceChar (int codePoint)

Determines if the specified character (Unicode code point) is a Unicode space character. A character is considered to be a space character if and only if it is specified to be a space character by the Unicode Standard. This method returns true if the character's general category type is any of the following:

Parameters

codePoint	the character (Unicode code point) to be tested.

Returns

true if the character is a space character; false otherwise.

public static boolean isSupplementaryCodePoint (int codePoint)

Determines whether the specified character (Unicode code point) is in the supplementary character range.

Parameters

codePoint	the character (Unicode code point) to be tested

Returns

true if the specified code point is between MIN_SUPPLEMENTARY_CODE_POINT and MAX_CODE_POINT inclusive; false otherwise.

public static boolean isSurrogate (char ch)

Determines if the given char value is a Unicode surrogate code unit.

Such values do not represent characters by themselves, but are used in the representation of supplementary characters in the UTF-16 encoding.

A char value is a surrogate code unit if and only if it is either a {@linkplain #isLowSurrogate(char) low-surrogate code unit} or a {@linkplain #isHighSurrogate(char) high-surrogate code unit}.

Parameters

ch	the `char` value to be tested.

Returns

true if the char value is between MIN_SURROGATE and MAX_SURROGATE inclusive; false otherwise.

public static boolean isSurrogatePair (char high, char low)

Determines whether the specified pair of char values is a valid Unicode surrogate pair.

This method is equivalent to the expression:

isHighSurrogate(high) && isLowSurrogate(low)

Parameters

high	the high-surrogate code value to be tested
low	the low-surrogate code value to be tested

Returns

true if the specified high and low-surrogate code values represent a valid surrogate pair; false otherwise.

public static boolean isTitleCase (int codePoint)

Determines if the specified character (Unicode code point) is a titlecase character.

A character is a titlecase character if its general category type, provided by getType(codePoint), is TITLECASE_LETTER.

Some characters look like pairs of Latin letters. For example, there is an uppercase letter that looks like "LJ" and has a corresponding lowercase letter that looks like "lj". A third form, which looks like "Lj", is the appropriate form to use when rendering a word in lowercase with initial capitals, as for a book title.

These are some of the Unicode characters for which this method returns true:

LATIN CAPITAL LETTER D WITH SMALL LETTER Z WITH CARON
LATIN CAPITAL LETTER L WITH SMALL LETTER J
LATIN CAPITAL LETTER N WITH SMALL LETTER J
LATIN CAPITAL LETTER D WITH SMALL LETTER Z

Many other Unicode characters are titlecase too.

Parameters

codePoint	the character (Unicode code point) to be tested.

Returns

true if the character is titlecase; false otherwise.

public static boolean isTitleCase (char ch)

Determines if the specified character is a titlecase character.

A character is a titlecase character if its general category type, provided by Character.getType(ch), is TITLECASE_LETTER.

These are some of the Unicode characters for which this method returns true:

LATIN CAPITAL LETTER D WITH SMALL LETTER Z WITH CARON
LATIN CAPITAL LETTER L WITH SMALL LETTER J
LATIN CAPITAL LETTER N WITH SMALL LETTER J
LATIN CAPITAL LETTER D WITH SMALL LETTER Z

Many other Unicode characters are titlecase too.

Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isTitleCase(int) method.

Parameters

ch	the character to be tested.

Returns

true if the character is titlecase; false otherwise.

public static boolean isUnicodeIdentifierPart (int codePoint)

Determines if the specified character (Unicode code point) may be part of a Unicode identifier as other than the first character.

A character may be part of a Unicode identifier if and only if one of the following statements is true:

it is a letter
it is a connecting punctuation character (such as '_')
it is a digit
it is a numeric letter (such as a Roman numeral character)
it is a combining mark
it is a non-spacing mark
isIdentifierIgnorable returns true for this character.

Parameters

codePoint	the character (Unicode code point) to be tested.

Returns

true if the character may be part of a Unicode identifier; false otherwise.

public static boolean isUnicodeIdentifierPart (char ch)

Determines if the specified character may be part of a Unicode identifier as other than the first character.

A character may be part of a Unicode identifier if and only if one of the following statements is true:

it is a letter
it is a connecting punctuation character (such as '_')
it is a digit
it is a numeric letter (such as a Roman numeral character)
it is a combining mark
it is a non-spacing mark
isIdentifierIgnorable returns true for this character.

Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isUnicodeIdentifierPart(int) method.

Parameters

ch	the character to be tested.

Returns

true if the character may be part of a Unicode identifier; false otherwise.

public static boolean isUnicodeIdentifierStart (int codePoint)

Determines if the specified character (Unicode code point) is permissible as the first character in a Unicode identifier.

A character may start a Unicode identifier if and only if one of the following conditions is true:

isLetter(codePoint) returns true
getType(codePoint) returns LETTER_NUMBER.

Parameters

codePoint	the character (Unicode code point) to be tested.

Returns

true if the character may start a Unicode identifier; false otherwise.

public static boolean isUnicodeIdentifierStart (char ch)

Determines if the specified character is permissible as the first character in a Unicode identifier.

A character may start a Unicode identifier if and only if one of the following conditions is true:

isLetter(ch) returns true
getType(ch) returns LETTER_NUMBER.

Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isUnicodeIdentifierStart(int) method.

Parameters

ch	the character to be tested.

Returns

true if the character may start a Unicode identifier; false otherwise.

public static boolean isUpperCase (char ch)

Determines if the specified character is an uppercase character.

A character is uppercase if its general category type, provided by Character.getType(ch), is UPPERCASE_LETTER. or it has contributory property Other_Uppercase as defined by the Unicode Standard.

The following are examples of uppercase characters:

 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
 '\u00C0' '\u00C1' '\u00C2' '\u00C3' '\u00C4' '\u00C5' '\u00C6' '\u00C7'
 '\u00C8' '\u00C9' '\u00CA' '\u00CB' '\u00CC' '\u00CD' '\u00CE' '\u00CF'
 '\u00D0' '\u00D1' '\u00D2' '\u00D3' '\u00D4' '\u00D5' '\u00D6' '\u00D8'
 '\u00D9' '\u00DA' '\u00DB' '\u00DC' '\u00DD' '\u00DE'

Many other Unicode characters are uppercase too.

Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isUpperCase(int) method.

Parameters

ch	the character to be tested.

Returns

true if the character is uppercase; false otherwise.

public static boolean isUpperCase (int codePoint)

Determines if the specified character (Unicode code point) is an uppercase character.

A character is uppercase if its general category type, provided by getType(codePoint), is UPPERCASE_LETTER, or it has contributory property Other_Uppercase as defined by the Unicode Standard.

The following are examples of uppercase characters:

 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
 '\u00C0' '\u00C1' '\u00C2' '\u00C3' '\u00C4' '\u00C5' '\u00C6' '\u00C7'
 '\u00C8' '\u00C9' '\u00CA' '\u00CB' '\u00CC' '\u00CD' '\u00CE' '\u00CF'
 '\u00D0' '\u00D1' '\u00D2' '\u00D3' '\u00D4' '\u00D5' '\u00D6' '\u00D8'
 '\u00D9' '\u00DA' '\u00DB' '\u00DC' '\u00DD' '\u00DE'

Many other Unicode characters are uppercase too.

Parameters

codePoint	the character (Unicode code point) to be tested.

Returns

true if the character is uppercase; false otherwise.

public static boolean isValidCodePoint (int codePoint)

Determines whether the specified code point is a valid Unicode code point value.

Parameters

codePoint	the Unicode code point to be tested

Returns

true if the specified code point value is between MIN_CODE_POINT and MAX_CODE_POINT inclusive; false otherwise.

public static boolean isWhitespace (int codePoint)

Determines if the specified character (Unicode code point) is white space according to Java. A character is a Java whitespace character if and only if it satisfies one of the following criteria:

It is a Unicode space character (SPACE_SEPARATOR, LINE_SEPARATOR, or PARAGRAPH_SEPARATOR) but is not also a non-breaking space ('\u00A0', '\u2007', '\u202F').
It is '\t', U+0009 HORIZONTAL TABULATION.
It is '\n', U+000A LINE FEED.
It is '\u000B', U+000B VERTICAL TABULATION.
It is '\f', U+000C FORM FEED.
It is '\r', U+000D CARRIAGE RETURN.
It is '\u001C', U+001C FILE SEPARATOR.
It is '\u001D', U+001D GROUP SEPARATOR.
It is '\u001E', U+001E RECORD SEPARATOR.
It is '\u001F', U+001F UNIT SEPARATOR.

Parameters

codePoint	the character (Unicode code point) to be tested.

Returns

true if the character is a Java whitespace character; false otherwise.

public static boolean isWhitespace (char ch)

Determines if the specified character is white space according to Java. A character is a Java whitespace character if and only if it satisfies one of the following criteria:

It is a Unicode space character (SPACE_SEPARATOR, LINE_SEPARATOR, or PARAGRAPH_SEPARATOR) but is not also a non-breaking space ('\u00A0', '\u2007', '\u202F').
It is '\t', U+0009 HORIZONTAL TABULATION.
It is '\n', U+000A LINE FEED.
It is '\u000B', U+000B VERTICAL TABULATION.
It is '\f', U+000C FORM FEED.
It is '\r', U+000D CARRIAGE RETURN.
It is '\u001C', U+001C FILE SEPARATOR.
It is '\u001D', U+001D GROUP SEPARATOR.
It is '\u001E', U+001E RECORD SEPARATOR.
It is '\u001F', U+001F UNIT SEPARATOR.

Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isWhitespace(int) method.

Parameters

ch	the character to be tested.

Returns

true if the character is a Java whitespace character; false otherwise.

public static char lowSurrogate (int codePoint)

Returns the trailing surrogate (a low surrogate code unit) of the surrogate pair representing the specified supplementary character (Unicode code point) in the UTF-16 encoding. If the specified character is not a supplementary character, an unspecified char is returned.

If isSupplementaryCodePoint(x) is true, then isLowSurrogate(lowSurrogate(x)) and toCodePoint(highSurrogate(x), lowSurrogate(x)) == x are also always true.

Parameters

codePoint	a supplementary character (Unicode code point)

Returns

the trailing surrogate code unit used to represent the character in the UTF-16 encoding

public static int offsetByCodePoints (CharSequence seq, int index, int codePointOffset)

Returns the index within the given char sequence that is offset from the given index by codePointOffset code points. Unpaired surrogates within the text range given by index and codePointOffset count as one code point each.

Parameters

seq	the char sequence
index	the index to be offset
codePointOffset	the offset in code points

Returns

the index within the char sequence

Throws

NullPointerException	if `seq` is null.
IndexOutOfBoundsException	if `index` is negative or larger then the length of the char sequence, or if `codePointOffset` is positive and the subsequence starting with `index` has fewer than `codePointOffset` code points, or if `codePointOffset` is negative and the subsequence before `index` has fewer than the absolute value of `codePointOffset` code points.

public static int offsetByCodePoints (char[] a, int start, int count, int index, int codePointOffset)

Returns the index within the given char subarray that is offset from the given index by codePointOffset code points. The start and count arguments specify a subarray of the char array. Unpaired surrogates within the text range given by index and codePointOffset count as one code point each.

Parameters

a	the `char` array
start	the index of the first `char` of the subarray
count	the length of the subarray in `char`s
index	the index to be offset
codePointOffset	the offset in code points

Returns

the index within the subarray

Throws

NullPointerException if a is null.

IndexOutOfBoundsException if start or count is negative, or if start + count is larger than the length of the given array, or if index is less than start or larger then start + count, or if codePointOffset is positive and the text range starting with index and ending with start + count - 1 has fewer than codePointOffset code points, or if codePointOffset is negative and the text range starting with start and ending with index - 1 has fewer than the absolute value of codePointOffset code points.

public static char reverseBytes (char ch)

Returns the value obtained by reversing the order of the bytes in the specified char value.

Parameters

ch	The `char` of which to reverse the byte order.

Returns

the value obtained by reversing (or, equivalently, swapping) the bytes in the specified char value.

public static int toChars (int codePoint, char[] dst, int dstIndex)

Converts the specified character (Unicode code point) to its UTF-16 representation. If the specified code point is a BMP (Basic Multilingual Plane or Plane 0) value, the same value is stored in dst[dstIndex], and 1 is returned. If the specified code point is a supplementary character, its surrogate values are stored in dst[dstIndex] (high-surrogate) and dst[dstIndex+1] (low-surrogate), and 2 is returned.

Parameters

codePoint	the character (Unicode code point) to be converted.
dst	an array of `char` in which the `codePoint`'s UTF-16 value is stored.
dstIndex	the start index into the `dst` array where the converted value is stored.

Returns

1 if the code point is a BMP code point, 2 if the code point is a supplementary code point.

Throws

IllegalArgumentException	if the specified `codePoint` is not a valid Unicode code point.
NullPointerException	if the specified `dst` is null.
IndexOutOfBoundsException	if `dstIndex` is negative or not less than `dst.length`, or if `dst` at `dstIndex` doesn't have enough array element(s) to store the resulting `char` value(s). (If `dstIndex` is equal to `dst.length-1` and the specified `codePoint` is a supplementary character, the high-surrogate value is not stored in `dst[dstIndex]`.)

public static char[] toChars (int codePoint)

Converts the specified character (Unicode code point) to its UTF-16 representation stored in a char array. If the specified code point is a BMP (Basic Multilingual Plane or Plane 0) value, the resulting char array has the same value as codePoint. If the specified code point is a supplementary code point, the resulting char array has the corresponding surrogate pair.

Parameters

codePoint	a Unicode code point

Returns

a char array having codePoint's UTF-16 representation.

Throws

IllegalArgumentException	if the specified `codePoint` is not a valid Unicode code point.

public static int toCodePoint (char high, char low)

Converts the specified surrogate pair to its supplementary code point value. This method does not validate the specified surrogate pair. The caller must validate it using isSurrogatePair if necessary.

Parameters

high	the high-surrogate code unit
low	the low-surrogate code unit

Returns

the supplementary code point composed from the specified surrogate pair.

public static int toLowerCase (int codePoint)

Converts the character (Unicode code point) argument to lowercase using case mapping information from the UnicodeData file.

Note that Character.isLowerCase(Character.toLowerCase(codePoint)) does not always return true for some ranges of characters, particularly those that are symbols or ideographs.

In general, String.toLowerCase() should be used to map characters to lowercase. String case mapping methods have several benefits over Character case mapping methods. String case mapping methods can perform locale-sensitive mappings, context-sensitive mappings, and 1:M character mappings, whereas the Character case mapping methods cannot.

Parameters

codePoint	the character (Unicode code point) to be converted.

Returns

the lowercase equivalent of the character (Unicode code point), if any; otherwise, the character itself.

public static char toLowerCase (char ch)

Converts the character argument to lowercase using case mapping information from the UnicodeData file.

Note that Character.isLowerCase(Character.toLowerCase(ch)) does not always return true for some ranges of characters, particularly those that are symbols or ideographs.

Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the toLowerCase(int) method.

Parameters

ch	the character to be converted.

Returns

the lowercase equivalent of the character, if any; otherwise, the character itself.

public String toString ()

Returns a String object representing this Character's value. The result is a string of length 1 whose sole component is the primitive char value represented by this Character object.

Returns

a string representation of this object.

public static String toString (char c)

Returns a String object representing the specified char. The result is a string of length 1 consisting solely of the specified char.

Parameters

c	the `char` to be converted

Returns

the string representation of the specified char

public static char toTitleCase (char ch)

Converts the character argument to titlecase using case mapping information from the UnicodeData file. If a character has no explicit titlecase mapping and is not itself a titlecase char according to UnicodeData, then the uppercase mapping is returned as an equivalent titlecase mapping. If the char argument is already a titlecase char, the same char value will be returned.

Note that Character.isTitleCase(Character.toTitleCase(ch)) does not always return true for some ranges of characters.

Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the toTitleCase(int) method.

Parameters

ch	the character to be converted.

Returns

the titlecase equivalent of the character, if any; otherwise, the character itself.

public static int toTitleCase (int codePoint)

Converts the character (Unicode code point) argument to titlecase using case mapping information from the UnicodeData file. If a character has no explicit titlecase mapping and is not itself a titlecase char according to UnicodeData, then the uppercase mapping is returned as an equivalent titlecase mapping. If the character argument is already a titlecase character, the same character value will be returned.

Note that Character.isTitleCase(Character.toTitleCase(codePoint)) does not always return true for some ranges of characters.

Parameters

codePoint	the character (Unicode code point) to be converted.

Returns

the titlecase equivalent of the character, if any; otherwise, the character itself.

public static char toUpperCase (char ch)

Converts the character argument to uppercase using case mapping information from the UnicodeData file.

Note that Character.isUpperCase(Character.toUpperCase(ch)) does not always return true for some ranges of characters, particularly those that are symbols or ideographs.

In general, String.toUpperCase() should be used to map characters to uppercase. String case mapping methods have several benefits over Character case mapping methods. String case mapping methods can perform locale-sensitive mappings, context-sensitive mappings, and 1:M character mappings, whereas the Character case mapping methods cannot.

Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the toUpperCase(int) method.

Parameters

ch	the character to be converted.

Returns

the uppercase equivalent of the character, if any; otherwise, the character itself.

public static int toUpperCase (int codePoint)

Converts the character (Unicode code point) argument to uppercase using case mapping information from the UnicodeData file.

Note that Character.isUpperCase(Character.toUpperCase(codePoint)) does not always return true for some ranges of characters, particularly those that are symbols or ideographs.

Parameters

codePoint	the character (Unicode code point) to be converted.

Returns

the uppercase equivalent of the character, if any; otherwise, the character itself.

public static Character valueOf (char c)

Returns a Character instance representing the specified char value. If a new Character instance is not required, this method should generally be used in preference to the constructor Character(char), as this method is likely to yield significantly better space and time performance by caching frequently requested values. This method will always cache values in the range '\u0000' to '\u007F', inclusive, and may cache other values outside of this range.

Parameters

c	a char value.

Returns

a Character instance representing c.

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Unicode Character Representations

Nested Class Summary

Constant Summary

Field Summary

Public Constructor Summary

Public Method Summary

Inherited Method Summary

Constants

public static final int BYTES

public static final byte COMBINING_SPACING_MARK

public static final byte CONNECTOR_PUNCTUATION

public static final byte CONTROL

public static final byte CURRENCY_SYMBOL

public static final byte DASH_PUNCTUATION

public static final byte DECIMAL_DIGIT_NUMBER

public static final byte DIRECTIONALITY_ARABIC_NUMBER

public static final byte DIRECTIONALITY_BOUNDARY_NEUTRAL

public static final byte DIRECTIONALITY_COMMON_NUMBER_SEPARATOR

public static final byte DIRECTIONALITY_EUROPEAN_NUMBER

public static final byte DIRECTIONALITY_EUROPEAN_NUMBER_SEPARATOR

public static final byte DIRECTIONALITY_EUROPEAN_NUMBER_TERMINATOR

public static final byte DIRECTIONALITY_LEFT_TO_RIGHT

public static final byte DIRECTIONALITY_LEFT_TO_RIGHT_EMBEDDING

public static final byte DIRECTIONALITY_LEFT_TO_RIGHT_OVERRIDE

public static final byte DIRECTIONALITY_NONSPACING_MARK

public static final byte DIRECTIONALITY_OTHER_NEUTRALS

public static final byte DIRECTIONALITY_PARAGRAPH_SEPARATOR

public static final byte DIRECTIONALITY_POP_DIRECTIONAL_FORMAT

public static final byte DIRECTIONALITY_RIGHT_TO_LEFT

public static final byte DIRECTIONALITY_RIGHT_TO_LEFT_ARABIC

public static final byte DIRECTIONALITY_RIGHT_TO_LEFT_EMBEDDING

public static final byte DIRECTIONALITY_RIGHT_TO_LEFT_OVERRIDE

public static final byte DIRECTIONALITY_SEGMENT_SEPARATOR

public static final byte DIRECTIONALITY_UNDEFINED

public static final byte DIRECTIONALITY_WHITESPACE

public static final byte ENCLOSING_MARK

public static final byte END_PUNCTUATION

public static final byte FINAL_QUOTE_PUNCTUATION

public static final byte FORMAT

public static final byte INITIAL_QUOTE_PUNCTUATION

public static final byte LETTER_NUMBER

public static final byte LINE_SEPARATOR

public static final byte LOWERCASE_LETTER

public static final byte MATH_SYMBOL

public static final int MAX_CODE_POINT

public static final char MAX_HIGH_SURROGATE

public static final char MAX_LOW_SURROGATE

public static final int MAX_RADIX

See Also

public static final char MAX_SURROGATE

public static final char MAX_VALUE

public static final int MIN_CODE_POINT

public static final char MIN_HIGH_SURROGATE

public static final char MIN_LOW_SURROGATE

public static final int MIN_RADIX

See Also

public static final int MIN_SUPPLEMENTARY_CODE_POINT

public static final char MIN_SURROGATE

public static final char MIN_VALUE

public static final byte MODIFIER_LETTER

public static final byte MODIFIER_SYMBOL

public static final byte NON_SPACING_MARK

public static final byte OTHER_LETTER

public static final byte OTHER_NUMBER

public static final byte OTHER_PUNCTUATION

public static final byte OTHER_SYMBOL

public static final byte PARAGRAPH_SEPARATOR

public static final byte PRIVATE_USE

public static final int SIZE

public static final byte SPACE_SEPARATOR

public static final byte START_PUNCTUATION

public static final byte SURROGATE

public static final byte TITLECASE_LETTER

public static final byte UNASSIGNED

public static final byte UPPERCASE_LETTER

Fields

public static final Class<Character> TYPE

Public Constructors

Character