Class Character
- All Implemented Interfaces:
Serializable
,Comparable<Character>
,Constable
Character
class wraps a value of the primitive
type char
in an object. An object of class
Character
contains a single field whose type is
char
.
In addition, this class provides a large number of static methods for determining a character's category (lowercase letter, digit, etc.) and for converting characters from uppercase to lowercase and vice versa.
Unicode Conformance
The fields and methods of class Character
are defined in terms
of character information from the Unicode Standard, specifically the
UnicodeData file that is part of the Unicode Character Database.
This file specifies properties including name and category for every
assigned Unicode code point or character range. The file is available
from the Unicode Consortium at
http://www.unicode.org.
Character information is based on the Unicode Standard, version 15.1.
The Java platform has supported different versions of the Unicode Standard over time. Upgrades to newer versions of the Unicode Standard occurred in the following Java releases, each indicating the new version:
Java release | Unicode version |
---|---|
Java SE 22 | Unicode 15.1 |
Java SE 20 | Unicode 15.0 |
Java SE 19 | Unicode 14.0 |
Java SE 15 | Unicode 13.0 |
Java SE 13 | Unicode 12.1 |
Java SE 12 | Unicode 11.0 |
Java SE 11 | Unicode 10.0 |
Java SE 9 | Unicode 8.0 |
Java SE 8 | Unicode 6.2 |
Java SE 7 | Unicode 6.0 |
Java SE 5.0 | Unicode 4.0 |
Java SE 1.4 | Unicode 3.0 |
JDK 1.1 | Unicode 2.0 |
JDK 1.0.2 | Unicode 1.1.5 |
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 treatchar
values from the surrogate ranges as undefined characters. For example,Character.isLetter('\uD840')
returnsfalse
, 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)
returnstrue
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.
This is a value-based class; programmers should treat instances that are equal as interchangeable and should not use instances for synchronization, or unpredictable behavior may occur. For example, in a future release, synchronization may fail.
- Since:
- 1.0
- External Specifications
- See Also:
-
Nested Class Summary
Modifier and TypeClassDescriptionstatic class
Instances of this class represent particular subsets of the Unicode character set.static final class
A family of character subsets representing the character blocks in the Unicode specification.static enum
A family of character subsets representing the character scripts defined in the Unicode Standard Annex #24: Script Names. -
Field Summary
Modifier and TypeFieldDescriptionstatic final int
The number of bytes used to represent achar
value in unsigned binary form.static final byte
General category "Mc" in the Unicode specification.static final byte
General category "Pc" in the Unicode specification.static final byte
General category "Cc" in the Unicode specification.static final byte
General category "Sc" in the Unicode specification.static final byte
General category "Pd" in the Unicode specification.static final byte
General category "Nd" in the Unicode specification.static final byte
Weak bidirectional character type "AN" in the Unicode specification.static final byte
Weak bidirectional character type "BN" in the Unicode specification.static final byte
Weak bidirectional character type "CS" in the Unicode specification.static final byte
Weak bidirectional character type "EN" in the Unicode specification.static final byte
Weak bidirectional character type "ES" in the Unicode specification.static final byte
Weak bidirectional character type "ET" in the Unicode specification.static final byte
Weak bidirectional character type "FSI" in the Unicode specification.static final byte
Strong bidirectional character type "L" in the Unicode specification.static final byte
Strong bidirectional character type "LRE" in the Unicode specification.static final byte
Weak bidirectional character type "LRI" in the Unicode specification.static final byte
Strong bidirectional character type "LRO" in the Unicode specification.static final byte
Weak bidirectional character type "NSM" in the Unicode specification.static final byte
Neutral bidirectional character type "ON" in the Unicode specification.static final byte
Neutral bidirectional character type "B" in the Unicode specification.static final byte
Weak bidirectional character type "PDF" in the Unicode specification.static final byte
Weak bidirectional character type "PDI" in the Unicode specification.static final byte
Strong bidirectional character type "R" in the Unicode specification.static final byte
Strong bidirectional character type "AL" in the Unicode specification.static final byte
Strong bidirectional character type "RLE" in the Unicode specification.static final byte
Weak bidirectional character type "RLI" in the Unicode specification.static final byte
Strong bidirectional character type "RLO" in the Unicode specification.static final byte
Neutral bidirectional character type "S" in the Unicode specification.static final byte
Undefined bidirectional character type.static final byte
Neutral bidirectional character type "WS" in the Unicode specification.static final byte
General category "Me" in the Unicode specification.static final byte
General category "Pe" in the Unicode specification.static final byte
General category "Pf" in the Unicode specification.static final byte
General category "Cf" in the Unicode specification.static final byte
General category "Pi" in the Unicode specification.static final byte
General category "Nl" in the Unicode specification.static final byte
General category "Zl" in the Unicode specification.static final byte
General category "Ll" in the Unicode specification.static final byte
General category "Sm" in the Unicode specification.static final int
The maximum value of a Unicode code point, constantU+10FFFF
.static final char
The maximum value of a Unicode high-surrogate code unit in the UTF-16 encoding, constant'\uDBFF'
.static final char
The maximum value of a Unicode low-surrogate code unit in the UTF-16 encoding, constant'\uDFFF'
.static final int
The maximum radix available for conversion to and from strings.static final char
The maximum value of a Unicode surrogate code unit in the UTF-16 encoding, constant'\uDFFF'
.static final char
The constant value of this field is the largest value of typechar
,'\uFFFF'
.static final int
The minimum value of a Unicode code point, constantU+0000
.static final char
The minimum value of a Unicode high-surrogate code unit in the UTF-16 encoding, constant'\uD800'
.static final char
The minimum value of a Unicode low-surrogate code unit in the UTF-16 encoding, constant'\uDC00'
.static final int
The minimum radix available for conversion to and from strings.static final int
The minimum value of a Unicode supplementary code point, constantU+10000
.static final char
The minimum value of a Unicode surrogate code unit in the UTF-16 encoding, constant'\uD800'
.static final char
The constant value of this field is the smallest value of typechar
,'\u0000'
.static final byte
General category "Lm" in the Unicode specification.static final byte
General category "Sk" in the Unicode specification.static final byte
General category "Mn" in the Unicode specification.static final byte
General category "Lo" in the Unicode specification.static final byte
General category "No" in the Unicode specification.static final byte
General category "Po" in the Unicode specification.static final byte
General category "So" in the Unicode specification.static final byte
General category "Zp" in the Unicode specification.static final byte
General category "Co" in the Unicode specification.static final int
The number of bits used to represent achar
value in unsigned binary form, constant16
.static final byte
General category "Zs" in the Unicode specification.static final byte
General category "Ps" in the Unicode specification.static final byte
General category "Cs" in the Unicode specification.static final byte
General category "Lt" in the Unicode specification.TheClass
instance representing the primitive typechar
.static final byte
General category "Cn" in the Unicode specification.static final byte
General category "Lu" in the Unicode specification. -
Constructor Summary
ConstructorDescriptionCharacter
(char value) Deprecated, for removal: This API element is subject to removal in a future version.It is rarely appropriate to use this constructor. -
Method Summary
Modifier and TypeMethodDescriptionstatic int
charCount
(int codePoint) Determines the number ofchar
values needed to represent the specified character (Unicode code point).char
Returns the value of thisCharacter
object.static int
codePointAt
(char[] a, int index) Returns the code point at the given index of thechar
array.static int
codePointAt
(char[] a, int index, int limit) Returns the code point at the given index of thechar
array, where only array elements withindex
less thanlimit
can be used.static int
codePointAt
(CharSequence seq, int index) Returns the code point at the given index of theCharSequence
.static int
codePointBefore
(char[] a, int index) Returns the code point preceding the given index of thechar
array.static int
codePointBefore
(char[] a, int index, int start) Returns the code point preceding the given index of thechar
array, where only array elements withindex
greater than or equal tostart
can be used.static int
codePointBefore
(CharSequence seq, int index) Returns the code point preceding the given index of theCharSequence
.static int
codePointCount
(char[] a, int offset, int count) Returns the number of Unicode code points in a subarray of thechar
array argument.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
codePointOf
(String name) Returns the code point value of the Unicode character specified by the given character name.static int
compare
(char x, char y) Compares twochar
values numerically.int
Compares twoCharacter
objects numerically.Returns anOptional
containing the nominal descriptor for this instance.static int
digit
(char ch, int radix) Returns the numeric value of the characterch
in the specified radix.static int
digit
(int codePoint, int radix) Returns the numeric value of the specified character (Unicode code point) in the specified radix.boolean
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 name of the specified charactercodePoint
, or null if the code point isunassigned
.static int
getNumericValue
(char ch) Returns theint
value that the specified Unicode character represents.static int
getNumericValue
(int codePoint) Returns theint
value that the specified character (Unicode code point) 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.int
hashCode()
Returns a hash code for thisCharacter
; equal to the result of invokingcharValue()
.static int
hashCode
(char value) Returns a hash code for achar
value; compatible withCharacter.hashCode()
.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 alphabetic.static boolean
isBmpCodePoint
(int codePoint) Determines whether the specified character (Unicode code point) is in the Basic Multilingual Plane (BMP).static boolean
isDefined
(char ch) Determines if a character is defined in Unicode.static boolean
isDefined
(int codePoint) Determines if a character (Unicode code point) 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
isEmoji
(int codePoint) Determines if the specified character (Unicode code point) is an Emoji.static boolean
isEmojiComponent
(int codePoint) Determines if the specified character (Unicode code point) is an Emoji Component.static boolean
isEmojiModifier
(int codePoint) Determines if the specified character (Unicode code point) is an Emoji Modifier.static boolean
isEmojiModifierBase
(int codePoint) Determines if the specified character (Unicode code point) is an Emoji Modifier Base.static boolean
isEmojiPresentation
(int codePoint) Determines if the specified character (Unicode code point) has the Emoji Presentation property by default.static boolean
isExtendedPictographic
(int codePoint) Determines if the specified character (Unicode code point) is an Extended Pictographic.static boolean
isHighSurrogate
(char ch) Determines if the givenchar
value is a Unicode high-surrogate code unit (also known as leading-surrogate code unit).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
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
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
(char ch) Determines if the specified character is permissible as the first character in a Java identifier.static boolean
isJavaIdentifierStart
(int codePoint) Determines if the character (Unicode code point) is permissible as the first character in a Java identifier.static boolean
isJavaLetter
(char ch) Deprecated.Replaced by isJavaIdentifierStart(char).static boolean
isJavaLetterOrDigit
(char ch) 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
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
isLowSurrogate
(char ch) Determines if the givenchar
value is a Unicode low-surrogate code unit (also known as trailing-surrogate code unit).static boolean
isMirrored
(char ch) Determines whether the character is mirrored according to the Unicode specification.static boolean
isMirrored
(int codePoint) Determines whether the specified character (Unicode code point) is mirrored according to the Unicode specification.static boolean
isSpace
(char ch) 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 givenchar
value is a Unicode surrogate code unit.static boolean
isSurrogatePair
(char high, char low) Determines whether the specified pair ofchar
values is a valid Unicode surrogate pair.static boolean
isTitleCase
(char ch) Determines if the specified character is a titlecase character.static boolean
isTitleCase
(int codePoint) Determines if the specified character (Unicode code point) is a titlecase 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
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
isUnicodeIdentifierStart
(char ch) Determines if the specified character is permissible as the first character in a Unicode identifier.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
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
(char ch) Determines if the specified character is white space according to Java.static boolean
isWhitespace
(int codePoint) Determines if the specified character (Unicode code point) 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
(char[] a, int start, int count, int index, int codePointOffset) Returns the index within the givenchar
subarray that is offset from the givenindex
bycodePointOffset
code points.static int
offsetByCodePoints
(CharSequence seq, int index, int codePointOffset) Returns the index within the given char sequence that is offset from the givenindex
bycodePointOffset
code points.static char
reverseBytes
(char ch) Returns the value obtained by reversing the order of the bytes in the specifiedchar
value.static char[]
toChars
(int codePoint) Converts the specified character (Unicode code point) to its UTF-16 representation stored in achar
array.static int
toChars
(int codePoint, char[] dst, int dstIndex) Converts the specified character (Unicode code point) to its UTF-16 representation.static int
toCodePoint
(char high, char low) Converts the specified surrogate pair to its supplementary code point value.static char
toLowerCase
(char ch) Converts the character argument to lowercase using case mapping information from the UnicodeData file.static int
toLowerCase
(int codePoint) Converts the character (Unicode code point) argument to lowercase using case mapping information from the UnicodeData file.toString()
Returns aString
object representing thisCharacter
's value.static String
toString
(char c) Returns aString
object representing the specifiedchar
.static String
toString
(int codePoint) Returns aString
object representing the specified character (Unicode code point).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 aCharacter
instance representing the specifiedchar
value.
-
Field Details
-
MIN_RADIX
public static final int MIN_RADIXThe 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 thedigit
method, theforDigit
method, and thetoString
method of classInteger
.- See Also:
-
MAX_RADIX
public static final int MAX_RADIXThe 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 thedigit
method, theforDigit
method, and thetoString
method of classInteger
.- See Also:
-
MIN_VALUE
public static final char MIN_VALUEThe constant value of this field is the smallest value of typechar
,'\u0000'
.- Since:
- 1.0.2
- See Also:
-
MAX_VALUE
public static final char MAX_VALUEThe constant value of this field is the largest value of typechar
,'\uFFFF'
.- Since:
- 1.0.2
- See Also:
-
TYPE
-
UNASSIGNED
public static final byte UNASSIGNEDGeneral category "Cn" in the Unicode specification.- Since:
- 1.1
- See Also:
-
UPPERCASE_LETTER
public static final byte UPPERCASE_LETTERGeneral category "Lu" in the Unicode specification.- Since:
- 1.1
- See Also:
-
LOWERCASE_LETTER
public static final byte LOWERCASE_LETTERGeneral category "Ll" in the Unicode specification.- Since:
- 1.1
- See Also:
-
TITLECASE_LETTER
public static final byte TITLECASE_LETTERGeneral category "Lt" in the Unicode specification.- Since:
- 1.1
- See Also:
-
MODIFIER_LETTER
public static final byte MODIFIER_LETTERGeneral category "Lm" in the Unicode specification.- Since:
- 1.1
- See Also:
-
OTHER_LETTER
public static final byte OTHER_LETTERGeneral category "Lo" in the Unicode specification.- Since:
- 1.1
- See Also:
-
NON_SPACING_MARK
public static final byte NON_SPACING_MARKGeneral category "Mn" in the Unicode specification.- Since:
- 1.1
- See Also:
-
ENCLOSING_MARK
public static final byte ENCLOSING_MARKGeneral category "Me" in the Unicode specification.- Since:
- 1.1
- See Also:
-
COMBINING_SPACING_MARK
public static final byte COMBINING_SPACING_MARKGeneral category "Mc" in the Unicode specification.- Since:
- 1.1
- See Also:
-
DECIMAL_DIGIT_NUMBER
public static final byte DECIMAL_DIGIT_NUMBERGeneral category "Nd" in the Unicode specification.- Since:
- 1.1
- See Also:
-
LETTER_NUMBER
public static final byte LETTER_NUMBERGeneral category "Nl" in the Unicode specification.- Since:
- 1.1
- See Also:
-
OTHER_NUMBER
public static final byte OTHER_NUMBERGeneral category "No" in the Unicode specification.- Since:
- 1.1
- See Also:
-
SPACE_SEPARATOR
public static final byte SPACE_SEPARATORGeneral category "Zs" in the Unicode specification.- Since:
- 1.1
- See Also:
-
LINE_SEPARATOR
public static final byte LINE_SEPARATORGeneral category "Zl" in the Unicode specification.- Since:
- 1.1
- See Also:
-
PARAGRAPH_SEPARATOR
public static final byte PARAGRAPH_SEPARATORGeneral category "Zp" in the Unicode specification.- Since:
- 1.1
- See Also:
-
CONTROL
public static final byte CONTROLGeneral category "Cc" in the Unicode specification.- Since:
- 1.1
- See Also:
-
FORMAT
public static final byte FORMATGeneral category "Cf" in the Unicode specification.- Since:
- 1.1
- See Also:
-
PRIVATE_USE
public static final byte PRIVATE_USEGeneral category "Co" in the Unicode specification.- Since:
- 1.1
- See Also:
-
SURROGATE
public static final byte SURROGATEGeneral category "Cs" in the Unicode specification.- Since:
- 1.1
- See Also:
-
DASH_PUNCTUATION
public static final byte DASH_PUNCTUATIONGeneral category "Pd" in the Unicode specification.- Since:
- 1.1
- See Also:
-
START_PUNCTUATION
public static final byte START_PUNCTUATIONGeneral category "Ps" in the Unicode specification.- Since:
- 1.1
- See Also:
-
END_PUNCTUATION
public static final byte END_PUNCTUATIONGeneral category "Pe" in the Unicode specification.- Since:
- 1.1
- See Also:
-
CONNECTOR_PUNCTUATION
public static final byte CONNECTOR_PUNCTUATIONGeneral category "Pc" in the Unicode specification.- Since:
- 1.1
- See Also:
-
OTHER_PUNCTUATION
public static final byte OTHER_PUNCTUATIONGeneral category "Po" in the Unicode specification.- Since:
- 1.1
- See Also:
-
MATH_SYMBOL
public static final byte MATH_SYMBOLGeneral category "Sm" in the Unicode specification.- Since:
- 1.1
- See Also:
-
CURRENCY_SYMBOL
public static final byte CURRENCY_SYMBOLGeneral category "Sc" in the Unicode specification.- Since:
- 1.1
- See Also:
-
MODIFIER_SYMBOL
public static final byte MODIFIER_SYMBOLGeneral category "Sk" in the Unicode specification.- Since:
- 1.1
- See Also:
-
OTHER_SYMBOL
public static final byte OTHER_SYMBOLGeneral category "So" in the Unicode specification.- Since:
- 1.1
- See Also:
-
INITIAL_QUOTE_PUNCTUATION
public static final byte INITIAL_QUOTE_PUNCTUATIONGeneral category "Pi" in the Unicode specification.- Since:
- 1.4
- See Also:
-
FINAL_QUOTE_PUNCTUATION
public static final byte FINAL_QUOTE_PUNCTUATIONGeneral category "Pf" in the Unicode specification.- Since:
- 1.4
- See Also:
-
DIRECTIONALITY_UNDEFINED
public static final byte DIRECTIONALITY_UNDEFINEDUndefined bidirectional character type. Undefinedchar
values have undefined directionality in the Unicode specification.- Since:
- 1.4
- See Also:
-
DIRECTIONALITY_LEFT_TO_RIGHT
public static final byte DIRECTIONALITY_LEFT_TO_RIGHTStrong bidirectional character type "L" in the Unicode specification.- Since:
- 1.4
- See Also:
-
DIRECTIONALITY_RIGHT_TO_LEFT
public static final byte DIRECTIONALITY_RIGHT_TO_LEFTStrong bidirectional character type "R" in the Unicode specification.- Since:
- 1.4
- See Also:
-
DIRECTIONALITY_RIGHT_TO_LEFT_ARABIC
public static final byte DIRECTIONALITY_RIGHT_TO_LEFT_ARABICStrong bidirectional character type "AL" in the Unicode specification.- Since:
- 1.4
- See Also:
-
DIRECTIONALITY_EUROPEAN_NUMBER
public static final byte DIRECTIONALITY_EUROPEAN_NUMBERWeak bidirectional character type "EN" in the Unicode specification.- Since:
- 1.4
- See Also:
-
DIRECTIONALITY_EUROPEAN_NUMBER_SEPARATOR
public static final byte DIRECTIONALITY_EUROPEAN_NUMBER_SEPARATORWeak bidirectional character type "ES" in the Unicode specification.- Since:
- 1.4
- See Also:
-
DIRECTIONALITY_EUROPEAN_NUMBER_TERMINATOR
public static final byte DIRECTIONALITY_EUROPEAN_NUMBER_TERMINATORWeak bidirectional character type "ET" in the Unicode specification.- Since:
- 1.4
- See Also:
-
DIRECTIONALITY_ARABIC_NUMBER
public static final byte DIRECTIONALITY_ARABIC_NUMBERWeak bidirectional character type "AN" in the Unicode specification.- Since:
- 1.4
- See Also:
-
DIRECTIONALITY_COMMON_NUMBER_SEPARATOR
public static final byte DIRECTIONALITY_COMMON_NUMBER_SEPARATORWeak bidirectional character type "CS" in the Unicode specification.- Since:
- 1.4
- See Also:
-
DIRECTIONALITY_NONSPACING_MARK
public static final byte DIRECTIONALITY_NONSPACING_MARKWeak bidirectional character type "NSM" in the Unicode specification.- Since:
- 1.4
- See Also:
-
DIRECTIONALITY_BOUNDARY_NEUTRAL
public static final byte DIRECTIONALITY_BOUNDARY_NEUTRALWeak bidirectional character type "BN" in the Unicode specification.- Since:
- 1.4
- See Also:
-
DIRECTIONALITY_PARAGRAPH_SEPARATOR
public static final byte DIRECTIONALITY_PARAGRAPH_SEPARATORNeutral bidirectional character type "B" in the Unicode specification.- Since:
- 1.4
- See Also:
-
DIRECTIONALITY_SEGMENT_SEPARATOR
public static final byte DIRECTIONALITY_SEGMENT_SEPARATORNeutral bidirectional character type "S" in the Unicode specification.- Since:
- 1.4
- See Also:
-
DIRECTIONALITY_WHITESPACE
public static final byte DIRECTIONALITY_WHITESPACENeutral bidirectional character type "WS" in the Unicode specification.- Since:
- 1.4
- See Also:
-
DIRECTIONALITY_OTHER_NEUTRALS
public static final byte DIRECTIONALITY_OTHER_NEUTRALSNeutral bidirectional character type "ON" in the Unicode specification.- Since:
- 1.4
- See Also:
-
DIRECTIONALITY_LEFT_TO_RIGHT_EMBEDDING
public static final byte DIRECTIONALITY_LEFT_TO_RIGHT_EMBEDDINGStrong bidirectional character type "LRE" in the Unicode specification.- Since:
- 1.4
- See Also:
-
DIRECTIONALITY_LEFT_TO_RIGHT_OVERRIDE
public static final byte DIRECTIONALITY_LEFT_TO_RIGHT_OVERRIDEStrong bidirectional character type "LRO" in the Unicode specification.- Since:
- 1.4
- See Also:
-
DIRECTIONALITY_RIGHT_TO_LEFT_EMBEDDING
public static final byte DIRECTIONALITY_RIGHT_TO_LEFT_EMBEDDINGStrong bidirectional character type "RLE" in the Unicode specification.- Since:
- 1.4
- See Also:
-
DIRECTIONALITY_RIGHT_TO_LEFT_OVERRIDE
public static final byte DIRECTIONALITY_RIGHT_TO_LEFT_OVERRIDEStrong bidirectional character type "RLO" in the Unicode specification.- Since:
- 1.4
- See Also:
-
DIRECTIONALITY_POP_DIRECTIONAL_FORMAT
public static final byte DIRECTIONALITY_POP_DIRECTIONAL_FORMATWeak bidirectional character type "PDF" in the Unicode specification.- Since:
- 1.4
- See Also:
-
DIRECTIONALITY_LEFT_TO_RIGHT_ISOLATE
public static final byte DIRECTIONALITY_LEFT_TO_RIGHT_ISOLATEWeak bidirectional character type "LRI" in the Unicode specification.- Since:
- 9
- See Also:
-
DIRECTIONALITY_RIGHT_TO_LEFT_ISOLATE
public static final byte DIRECTIONALITY_RIGHT_TO_LEFT_ISOLATEWeak bidirectional character type "RLI" in the Unicode specification.- Since:
- 9
- See Also:
-
DIRECTIONALITY_FIRST_STRONG_ISOLATE
public static final byte DIRECTIONALITY_FIRST_STRONG_ISOLATEWeak bidirectional character type "FSI" in the Unicode specification.- Since:
- 9
- See Also:
-
DIRECTIONALITY_POP_DIRECTIONAL_ISOLATE
public static final byte DIRECTIONALITY_POP_DIRECTIONAL_ISOLATEWeak bidirectional character type "PDI" in the Unicode specification.- Since:
- 9
- See Also:
-
MIN_HIGH_SURROGATE
public static final char MIN_HIGH_SURROGATEThe 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.- Since:
- 1.5
- See Also:
-
MAX_HIGH_SURROGATE
public static final char MAX_HIGH_SURROGATEThe 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.- Since:
- 1.5
- See Also:
-
MIN_LOW_SURROGATE
public static final char MIN_LOW_SURROGATEThe 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.- Since:
- 1.5
- See Also:
-
MAX_LOW_SURROGATE
public static final char MAX_LOW_SURROGATEThe 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.- Since:
- 1.5
- See Also:
-
MIN_SURROGATE
public static final char MIN_SURROGATEThe minimum value of a Unicode surrogate code unit in the UTF-16 encoding, constant'\uD800'
.- Since:
- 1.5
- See Also:
-
MAX_SURROGATE
public static final char MAX_SURROGATEThe maximum value of a Unicode surrogate code unit in the UTF-16 encoding, constant'\uDFFF'
.- Since:
- 1.5
- See Also:
-
MIN_SUPPLEMENTARY_CODE_POINT
public static final int MIN_SUPPLEMENTARY_CODE_POINTThe minimum value of a Unicode supplementary code point, constantU+10000
.- Since:
- 1.5
- See Also:
-
MIN_CODE_POINT
public static final int MIN_CODE_POINTThe minimum value of a Unicode code point, constantU+0000
.- Since:
- 1.5
- See Also:
-
MAX_CODE_POINT
public static final int MAX_CODE_POINTThe maximum value of a Unicode code point, constantU+10FFFF
.- Since:
- 1.5
- See Also:
-
SIZE
public static final int SIZEThe number of bits used to represent achar
value in unsigned binary form, constant16
.- Since:
- 1.5
- See Also:
-
BYTES
public static final int BYTESThe number of bytes used to represent achar
value in unsigned binary form.- Since:
- 1.8
- See Also:
-
-
Constructor Details
-
Character
Deprecated, for removal: This API element is subject to removal in a future version.It is rarely appropriate to use this constructor. The static factoryvalueOf(char)
is generally a better choice, as it is likely to yield significantly better space and time performance.Constructs a newly allocatedCharacter
object that represents the specifiedchar
value.- Parameters:
value
- the value to be represented by theCharacter
object.
-
-
Method Details
-
describeConstable
Returns anOptional
containing the nominal descriptor for this instance.- Specified by:
describeConstable
in interfaceConstable
- Returns:
- an
Optional
describing the Character instance - Since:
- 15
-
valueOf
Returns aCharacter
instance representing the specifiedchar
value. If a newCharacter
instance is not required, this method should generally be used in preference to the constructorCharacter(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 representingc
. - Since:
- 1.5
-
charValue
public char charValue()Returns the value of thisCharacter
object.- Returns:
- the primitive
char
value represented by this object.
-
hashCode
-
hashCode
public static int hashCode(char value) Returns a hash code for achar
value; compatible withCharacter.hashCode()
.- Parameters:
value
- Thechar
for which to return a hash code.- Returns:
- a hash code value for a
char
value. - Since:
- 1.8
-
equals
Compares this object against the specified object. The result istrue
if and only if the argument is notnull
and is aCharacter
object that represents the samechar
value as this object. -
toString
-
toString
Returns aString
object representing the specifiedchar
. The result is a string of length 1 consisting solely of the specifiedchar
.- API Note:
- This method cannot handle supplementary characters. To support
all Unicode characters, including supplementary characters, use
the
toString(int)
method. - Parameters:
c
- thechar
to be converted- Returns:
- the string representation of the specified
char
- Since:
- 1.4
-
toString
Returns aString
object representing the specified character (Unicode code point). The result is a string of length 1 or 2, consisting solely of the specifiedcodePoint
.- Parameters:
codePoint
- thecodePoint
to be converted- Returns:
- the string representation of the specified
codePoint
- Throws:
IllegalArgumentException
- if the specifiedcodePoint
is not a valid Unicode code point.- Since:
- 11
-
isValidCodePoint
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 betweenMIN_CODE_POINT
andMAX_CODE_POINT
inclusive;false
otherwise.- Since:
- 1.5
-
isBmpCodePoint
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 singlechar
. -
isSupplementaryCodePoint
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 betweenMIN_SUPPLEMENTARY_CODE_POINT
andMAX_CODE_POINT
inclusive;false
otherwise.- Since:
- 1.5
-
isHighSurrogate
public static boolean isHighSurrogate(char ch) Determines if the givenchar
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
- thechar
value to be tested.- Returns:
true
if thechar
value is betweenMIN_HIGH_SURROGATE
andMAX_HIGH_SURROGATE
inclusive;false
otherwise.- Since:
- 1.5
- See Also:
-
isLowSurrogate
public static boolean isLowSurrogate(char ch) Determines if the givenchar
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
- thechar
value to be tested.- Returns:
true
if thechar
value is betweenMIN_LOW_SURROGATE
andMAX_LOW_SURROGATE
inclusive;false
otherwise.- Since:
- 1.5
- See Also:
-
isSurrogate
public static boolean isSurrogate(char ch) Determines if the givenchar
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 low-surrogate code unit or a high-surrogate code unit.
- Parameters:
ch
- thechar
value to be tested.- Returns:
true
if thechar
value is betweenMIN_SURROGATE
andMAX_SURROGATE
inclusive;false
otherwise.- Since:
- 1.7
-
isSurrogatePair
public static boolean isSurrogatePair(char high, char low) Determines whether the specified pair ofchar
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 testedlow
- 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.- Since:
- 1.5
-
charCount
public static int charCount(int codePoint) Determines the number ofchar
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.
- Since:
- 1.5
- See Also:
-
toCodePoint
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 usingisSurrogatePair
if necessary.- Parameters:
high
- the high-surrogate code unitlow
- the low-surrogate code unit- Returns:
- the supplementary code point composed from the specified surrogate pair.
- Since:
- 1.5
-
codePointAt
Returns the code point at the given index of theCharSequence
. If thechar
value at the given index in theCharSequence
is in the high-surrogate range, the following index is less than the length of theCharSequence
, and thechar
value at the following index is in the low-surrogate range, then the supplementary code point corresponding to this surrogate pair is returned. Otherwise, thechar
value at the given index is returned.- Parameters:
seq
- a sequence ofchar
values (Unicode code units)index
- the index to thechar
values (Unicode code units) inseq
to be converted- Returns:
- the Unicode code point at the given index
- Throws:
NullPointerException
- ifseq
is null.IndexOutOfBoundsException
- if the valueindex
is negative or not less thanseq.length()
.- Since:
- 1.5
-
codePointAt
public static int codePointAt(char[] a, int index) Returns the code point at the given index of thechar
array. If thechar
value at the given index in thechar
array is in the high-surrogate range, the following index is less than the length of thechar
array, and thechar
value at the following index is in the low-surrogate range, then the supplementary code point corresponding to this surrogate pair is returned. Otherwise, thechar
value at the given index is returned.- Parameters:
a
- thechar
arrayindex
- the index to thechar
values (Unicode code units) in thechar
array to be converted- Returns:
- the Unicode code point at the given index
- Throws:
NullPointerException
- ifa
is null.IndexOutOfBoundsException
- if the valueindex
is negative or not less than the length of thechar
array.- Since:
- 1.5
-
codePointAt
public static int codePointAt(char[] a, int index, int limit) Returns the code point at the given index of thechar
array, where only array elements withindex
less thanlimit
can be used. If thechar
value at the given index in thechar
array is in the high-surrogate range, the following index is less than thelimit
, and thechar
value at the following index is in the low-surrogate range, then the supplementary code point corresponding to this surrogate pair is returned. Otherwise, thechar
value at the given index is returned.- Parameters:
a
- thechar
arrayindex
- the index to thechar
values (Unicode code units) in thechar
array to be convertedlimit
- the index after the last array element that can be used in thechar
array- Returns:
- the Unicode code point at the given index
- Throws:
NullPointerException
- ifa
is null.IndexOutOfBoundsException
- if theindex
argument is negative or not less than thelimit
argument, or if thelimit
argument is negative or greater than the length of thechar
array.- Since:
- 1.5
-
codePointBefore
Returns the code point preceding the given index of theCharSequence
. If thechar
value at(index - 1)
in theCharSequence
is in the low-surrogate range,(index - 2)
is not negative, and thechar
value at(index - 2)
in theCharSequence
is in the high-surrogate range, then the supplementary code point corresponding to this surrogate pair is returned. Otherwise, thechar
value at(index - 1)
is returned.- Parameters:
seq
- theCharSequence
instanceindex
- the index following the code point that should be returned- Returns:
- the Unicode code point value before the given index.
- Throws:
NullPointerException
- ifseq
is null.IndexOutOfBoundsException
- if theindex
argument is less than 1 or greater thanseq.length()
.- Since:
- 1.5
-
codePointBefore
public static int codePointBefore(char[] a, int index) Returns the code point preceding the given index of thechar
array. If thechar
value at(index - 1)
in thechar
array is in the low-surrogate range,(index - 2)
is not negative, and thechar
value at(index - 2)
in thechar
array is in the high-surrogate range, then the supplementary code point corresponding to this surrogate pair is returned. Otherwise, thechar
value at(index - 1)
is returned.- Parameters:
a
- thechar
arrayindex
- the index following the code point that should be returned- Returns:
- the Unicode code point value before the given index.
- Throws:
NullPointerException
- ifa
is null.IndexOutOfBoundsException
- if theindex
argument is less than 1 or greater than the length of thechar
array- Since:
- 1.5
-
codePointBefore
public static int codePointBefore(char[] a, int index, int start) Returns the code point preceding the given index of thechar
array, where only array elements withindex
greater than or equal tostart
can be used. If thechar
value at(index - 1)
in thechar
array is in the low-surrogate range,(index - 2)
is not less thanstart
, and thechar
value at(index - 2)
in thechar
array is in the high-surrogate range, then the supplementary code point corresponding to this surrogate pair is returned. Otherwise, thechar
value at(index - 1)
is returned.- Parameters:
a
- thechar
arrayindex
- the index following the code point that should be returnedstart
- the index of the first array element in thechar
array- Returns:
- the Unicode code point value before the given index.
- Throws:
NullPointerException
- ifa
is null.IndexOutOfBoundsException
- if theindex
argument is not greater than thestart
argument or is greater than the length of thechar
array, or if thestart
argument is negative or not less than the length of thechar
array.- Since:
- 1.5
-
highSurrogate
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 unspecifiedchar
is returned.If
isSupplementaryCodePoint(x)
istrue
, thenisHighSurrogate
(highSurrogate(x))
andtoCodePoint
(highSurrogate(x),
lowSurrogate
(x)) == x
are also alwaystrue
.- Parameters:
codePoint
- a supplementary character (Unicode code point)- Returns:
- the leading surrogate code unit used to represent the character in the UTF-16 encoding
- Since:
- 1.7
-
lowSurrogate
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 unspecifiedchar
is returned.If
isSupplementaryCodePoint(x)
istrue
, thenisLowSurrogate
(lowSurrogate(x))
andtoCodePoint
(
highSurrogate
(x), lowSurrogate(x)) == x
are also alwaystrue
.- Parameters:
codePoint
- a supplementary character (Unicode code point)- Returns:
- the trailing surrogate code unit used to represent the character in the UTF-16 encoding
- Since:
- 1.7
-
toChars
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 indst[dstIndex]
, and 1 is returned. If the specified code point is a supplementary character, its surrogate values are stored indst[dstIndex]
(high-surrogate) anddst[dstIndex+1]
(low-surrogate), and 2 is returned.- Parameters:
codePoint
- the character (Unicode code point) to be converted.dst
- an array ofchar
in which thecodePoint
's UTF-16 value is stored.dstIndex
- the start index into thedst
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 specifiedcodePoint
is not a valid Unicode code point.NullPointerException
- if the specifieddst
is null.IndexOutOfBoundsException
- ifdstIndex
is negative or not less thandst.length
, or ifdst
atdstIndex
doesn't have enough array element(s) to store the resultingchar
value(s). (IfdstIndex
is equal todst.length-1
and the specifiedcodePoint
is a supplementary character, the high-surrogate value is not stored indst[dstIndex]
.)- Since:
- 1.5
-
toChars
public static char[] toChars(int codePoint) Converts the specified character (Unicode code point) to its UTF-16 representation stored in achar
array. If the specified code point is a BMP (Basic Multilingual Plane or Plane 0) value, the resultingchar
array has the same value ascodePoint
. If the specified code point is a supplementary code point, the resultingchar
array has the corresponding surrogate pair.- Parameters:
codePoint
- a Unicode code point- Returns:
- a
char
array havingcodePoint
's UTF-16 representation. - Throws:
IllegalArgumentException
- if the specifiedcodePoint
is not a valid Unicode code point.- Since:
- 1.5
-
codePointCount
Returns the number of Unicode code points in the text range of the specified char sequence. The text range begins at the specifiedbeginIndex
and extends to thechar
at indexendIndex - 1
. Thus the length (inchar
s) of the text range isendIndex-beginIndex
. Unpaired surrogates within the text range count as one code point each.- Parameters:
seq
- the char sequencebeginIndex
- the index to the firstchar
of the text range.endIndex
- the index after the lastchar
of the text range.- Returns:
- the number of Unicode code points in the specified text range
- Throws:
NullPointerException
- ifseq
is null.IndexOutOfBoundsException
- if thebeginIndex
is negative, orendIndex
is larger than the length of the given sequence, orbeginIndex
is larger thanendIndex
.- Since:
- 1.5
-
codePointCount
public static int codePointCount(char[] a, int offset, int count) Returns the number of Unicode code points in a subarray of thechar
array argument. Theoffset
argument is the index of the firstchar
of the subarray and thecount
argument specifies the length of the subarray inchar
s. Unpaired surrogates within the subarray count as one code point each.- Parameters:
a
- thechar
arrayoffset
- the index of the firstchar
in the givenchar
arraycount
- the length of the subarray inchar
s- Returns:
- the number of Unicode code points in the specified subarray
- Throws:
NullPointerException
- ifa
is null.IndexOutOfBoundsException
- ifoffset
orcount
is negative, or ifoffset + count
is larger than the length of the given array.- Since:
- 1.5
-
offsetByCodePoints
Returns the index within the given char sequence that is offset from the givenindex
bycodePointOffset
code points. Unpaired surrogates within the text range given byindex
andcodePointOffset
count as one code point each.- Parameters:
seq
- the char sequenceindex
- the index to be offsetcodePointOffset
- the offset in code points- Returns:
- the index within the char sequence
- Throws:
NullPointerException
- ifseq
is null.IndexOutOfBoundsException
- ifindex
is negative or larger than the length of the char sequence, or ifcodePointOffset
is positive and the subsequence starting withindex
has fewer thancodePointOffset
code points, or ifcodePointOffset
is negative and the subsequence beforeindex
has fewer than the absolute value ofcodePointOffset
code points.- Since:
- 1.5
-
offsetByCodePoints
public static int offsetByCodePoints(char[] a, int start, int count, int index, int codePointOffset) Returns the index within the givenchar
subarray that is offset from the givenindex
bycodePointOffset
code points. Thestart
andcount
arguments specify a subarray of thechar
array. Unpaired surrogates within the text range given byindex
andcodePointOffset
count as one code point each.- Parameters:
a
- thechar
arraystart
- the index of the firstchar
of the subarraycount
- the length of the subarray inchar
sindex
- the index to be offsetcodePointOffset
- the offset in code points- Returns:
- the index within the subarray
- Throws:
NullPointerException
- ifa
is null.IndexOutOfBoundsException
- ifstart
orcount
is negative, or ifstart + count
is larger than the length of the given array, or ifindex
is less thanstart
or larger thenstart + count
, or ifcodePointOffset
is positive and the text range starting withindex
and ending withstart + count - 1
has fewer thancodePointOffset
code points, or ifcodePointOffset
is negative and the text range starting withstart
and ending withindex - 1
has fewer than the absolute value ofcodePointOffset
code points.- Since:
- 1.5
-
isLowerCase
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)
, isLOWERCASE_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.- See Also:
-
isLowerCase
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)
, isLOWERCASE_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.- Since:
- 1.5
- See Also:
-
isUpperCase
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)
, isUPPERCASE_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.- Since:
- 1.0
- See Also:
-
isUpperCase
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)
, isUPPERCASE_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.- Since:
- 1.5
- See Also:
-
isTitleCase
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)
, isTITLECASE_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.
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.- Since:
- 1.0.2
- See Also:
-
isTitleCase
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)
, isTITLECASE_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.- Since:
- 1.5
- See Also:
-
isDigit
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)
, isDECIMAL_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
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.- See Also:
-
isDigit
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)
, isDECIMAL_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
- Parameters:
codePoint
- the character (Unicode code point) to be tested.- Returns:
true
if the character is a digit;false
otherwise.- Since:
- 1.5
- See Also:
-
isDefined
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.- Since:
- 1.0.2
- See Also:
-
isDefined
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.- Since:
- 1.5
- See Also:
-
isLetter
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
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.- See Also:
-
-
isLetter
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
- Parameters:
codePoint
- the character (Unicode code point) to be tested.- Returns:
true
if the character is a letter;false
otherwise.- Since:
- 1.5
- See Also:
-
-
isLetterOrDigit
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)
orCharacter.isDigit(char ch)
returnstrue
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.- Since:
- 1.0.2
- See Also:
-
isLetterOrDigit
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)
orisDigit(codePoint)
returnstrue
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.- Since:
- 1.5
- See Also:
-
isJavaLetter
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 conditions is true:
-
isLetter(ch)
returnstrue
-
getType(ch)
returnsLETTER_NUMBER
-
ch
is a currency symbol (such as'$'
) -
ch
is a connecting punctuation character (such as'_'
).
- Parameters:
ch
- the character to be tested.- Returns:
true
if the character may start a Java identifier;false
otherwise.- Since:
- 1.0.2
- See Also:
-
-
isJavaLetterOrDigit
Deprecated.Replaced by isJavaIdentifierPart(char).Determines if the specified character may be part of a Java identifier as other than the first character.A character may be part of a Java identifier if and only if one of the following conditions is true:
- it is a letter
- it is a currency symbol (such as
'$'
) - 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
returnstrue
for the character.
- Parameters:
ch
- the character to be tested.- Returns:
true
if the character may be part of a Java identifier;false
otherwise.- Since:
- 1.0.2
- See Also:
-
isAlphabetic
public static boolean isAlphabetic(int codePoint) Determines if the specified character (Unicode code point) is alphabetic.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
- Parameters:
codePoint
- the character (Unicode code point) to be tested.- Returns:
true
if the character is a Unicode alphabet character,false
otherwise.- Since:
- 1.7
-
-
isIdeographic
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.- Since:
- 1.7
-
isJavaIdentifierStart
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)
returnstrue
-
getType(ch)
returnsLETTER_NUMBER
-
ch
is a currency symbol (such as'$'
) -
ch
is a connecting punctuation character (such as'_'
).
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the
isJavaIdentifierStart(int)
method.- Parameters:
ch
- the character to be tested.- Returns:
true
if the character may start a Java identifier;false
otherwise.- Since:
- 1.1
- See Also:
-
-
isJavaIdentifierStart
public static boolean isJavaIdentifierStart(int codePoint) Determines if the character (Unicode code point) is permissible as the first character in a Java identifier.A character may start a Java identifier if and only if one of the following conditions is true:
-
isLetter(codePoint)
returnstrue
-
getType(codePoint)
returnsLETTER_NUMBER
- the referenced character is a currency symbol (such as
'$'
) - 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.- Since:
- 1.5
- See Also:
-
-
isJavaIdentifierPart
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 conditions are true:
- it is a letter
- it is a currency symbol (such as
'$'
) - it is a connecting punctuation character (such as
'_'
) - it is a digit
- it is a numeric letter (such as a Roman numeral character)
- it is a combining mark
- it is a non-spacing mark
-
isIdentifierIgnorable
returnstrue
for the character
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the
isJavaIdentifierPart(int)
method.- Parameters:
ch
- the character to be tested.- Returns:
true
if the character may be part of a Java identifier;false
otherwise.- Since:
- 1.1
- See Also:
-
isJavaIdentifierPart
public static boolean isJavaIdentifierPart(int codePoint) Determines if the character (Unicode code point) may be part of a Java identifier as other than the first character.A character may be part of a Java identifier if any of the following conditions are true:
- it is a letter
- it is a currency symbol (such as
'$'
) - 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)
returnstrue
for the code point
- Parameters:
codePoint
- the character (Unicode code point) to be tested.- Returns:
true
if the character may be part of a Java identifier;false
otherwise.- Since:
- 1.5
- See Also:
-
isUnicodeIdentifierStart
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)
returnstrue
-
getType(ch)
returnsLETTER_NUMBER
. - it is an
Other_ID_Start
character.
This method conforms to UAX31-R1: Default Identifiers requirement of the Unicode Standard, with the following profile of UAX31:
Start := ID_Start + 'VERTICAL TILDE' (U+2E2F)
'VERTICAL TILDE'
is added toStart
for backward compatibility.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.- Since:
- 1.1
- External Specifications
- See Also:
-
-
isUnicodeIdentifierStart
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)
returnstrue
-
getType(codePoint)
returnsLETTER_NUMBER
. - it is an
Other_ID_Start
character.
This method conforms to UAX31-R1: Default Identifiers requirement of the Unicode Standard, with the following profile of UAX31:
Start := ID_Start + 'VERTICAL TILDE' (U+2E2F)
'VERTICAL TILDE'
is added toStart
for backward compatibility.- Parameters:
codePoint
- the character (Unicode code point) to be tested.- Returns:
true
if the character may start a Unicode identifier;false
otherwise.- Since:
- 1.5
- External Specifications
- See Also:
-
-
isUnicodeIdentifierPart
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
returnstrue
for this character. - it is an
Other_ID_Start
character. - it is an
Other_ID_Continue
character.
This method conforms to UAX31-R1: Default Identifiers requirement of the Unicode Standard, with the following profile of UAX31:
Continue := Start + ID_Continue + ignorable Medial := empty ignorable := isIdentifierIgnorable(char) returns true for the character
ignorable
is added toContinue
for backward compatibility.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.- Since:
- 1.1
- External Specifications
- See Also:
-
isUnicodeIdentifierPart
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
returnstrue
for this character. - it is an
Other_ID_Start
character. - it is an
Other_ID_Continue
character.
This method conforms to UAX31-R1: Default Identifiers requirement of the Unicode Standard, with the following profile of UAX31:
Continue := Start + ID_Continue + ignorable Medial := empty ignorable := isIdentifierIgnorable(int) returns true for the character
ignorable
is added toContinue
for backward compatibility.- Parameters:
codePoint
- the character (Unicode code point) to be tested.- Returns:
true
if the character may be part of a Unicode identifier;false
otherwise.- Since:
- 1.5
- External Specifications
- See Also:
-
isIdentifierIgnorable
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.- Since:
- 1.1
- See Also:
- ISO control characters that are not whitespace
-
isIdentifierIgnorable
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.- Since:
- 1.5
- See Also:
- ISO control characters that are not whitespace
-
isEmoji
public static boolean isEmoji(int codePoint) Determines if the specified character (Unicode code point) is an Emoji.A character is considered to be an Emoji if and only if it has the
Emoji
property, defined in Unicode Emoji (Technical Standard #51).- Parameters:
codePoint
- the character (Unicode code point) to be tested.- Returns:
true
if the character is an Emoji;false
otherwise.- Since:
- 21
-
isEmojiPresentation
public static boolean isEmojiPresentation(int codePoint) Determines if the specified character (Unicode code point) has the Emoji Presentation property by default.A character is considered to have the Emoji Presentation property if and only if it has the
Emoji_Presentation
property, defined in Unicode Emoji (Technical Standard #51).- Parameters:
codePoint
- the character (Unicode code point) to be tested.- Returns:
true
if the character has the Emoji Presentation property;false
otherwise.- Since:
- 21
-
isEmojiModifier
public static boolean isEmojiModifier(int codePoint) Determines if the specified character (Unicode code point) is an Emoji Modifier.A character is considered to be an Emoji Modifier if and only if it has the
Emoji_Modifier
property, defined in Unicode Emoji (Technical Standard #51).- Parameters:
codePoint
- the character (Unicode code point) to be tested.- Returns:
true
if the character is an Emoji Modifier;false
otherwise.- Since:
- 21
-
isEmojiModifierBase
public static boolean isEmojiModifierBase(int codePoint) Determines if the specified character (Unicode code point) is an Emoji Modifier Base.A character is considered to be an Emoji Modifier Base if and only if it has the
Emoji_Modifier_Base
property, defined in Unicode Emoji (Technical Standard #51).- Parameters:
codePoint
- the character (Unicode code point) to be tested.- Returns:
true
if the character is an Emoji Modifier Base;false
otherwise.- Since:
- 21
-
isEmojiComponent
public static boolean isEmojiComponent(int codePoint) Determines if the specified character (Unicode code point) is an Emoji Component.A character is considered to be an Emoji Component if and only if it has the
Emoji_Component
property, defined in Unicode Emoji (Technical Standard #51).- Parameters:
codePoint
- the character (Unicode code point) to be tested.- Returns:
true
if the character is an Emoji Component;false
otherwise.- Since:
- 21
-
isExtendedPictographic
public static boolean isExtendedPictographic(int codePoint) Determines if the specified character (Unicode code point) is an Extended Pictographic.A character is considered to be an Extended Pictographic if and only if it has the
Extended_Pictographic
property, defined in Unicode Emoji (Technical Standard #51).- Parameters:
codePoint
- the character (Unicode code point) to be tested.- Returns:
true
if the character is an Extended Pictographic;false
otherwise.- Since:
- 21
-
toLowerCase
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 returntrue
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 overCharacter
case mapping methods.String
case mapping methods can perform locale-sensitive mappings, context-sensitive mappings, and 1:M character mappings, whereas theCharacter
case mapping methods cannot.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.
- See Also:
-
toLowerCase
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 returntrue
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 overCharacter
case mapping methods.String
case mapping methods can perform locale-sensitive mappings, context-sensitive mappings, and 1:M character mappings, whereas theCharacter
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.
- Since:
- 1.5
- See Also:
-
toUpperCase
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 returntrue
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 overCharacter
case mapping methods.String
case mapping methods can perform locale-sensitive mappings, context-sensitive mappings, and 1:M character mappings, whereas theCharacter
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.
- See Also:
-
toUpperCase
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 returntrue
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 overCharacter
case mapping methods.String
case mapping methods can perform locale-sensitive mappings, context-sensitive mappings, and 1:M character mappings, whereas theCharacter
case mapping methods cannot.- Parameters:
codePoint
- the character (Unicode code point) to be converted.- Returns:
- the uppercase equivalent of the character, if any; otherwise, the character itself.
- Since:
- 1.5
- See Also:
-
toTitleCase
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 thechar
argument is already a titlecasechar
, the samechar
value will be returned.Note that
Character.isTitleCase(Character.toTitleCase(ch))
does not always returntrue
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.
- Since:
- 1.0.2
- See Also:
-
toTitleCase
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 returntrue
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.
- Since:
- 1.5
- See Also:
-
digit
public static int digit(char ch, int radix) Returns the numeric value of the characterch
in the specified radix.If the radix is not in the range
MIN_RADIX
≤radix
≤MAX_RADIX
or if the value ofch
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
istrue
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 thanradix + '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 thanradix + '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 thanradix + '\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 thanradix + '\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.
- See Also:
- The method
-
digit
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)
istrue
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 thanradix + '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 thanradix + '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 thanradix + '\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 thanradix + '\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.
- Since:
- 1.5
- See Also:
- The method
-
getNumericValue
public static int getNumericValue(char ch) Returns theint
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.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 thesechar
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.
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 but the value can not be represented as a nonnegativeint
value; -1 if the character has no numeric value. - Since:
- 1.1
- See Also:
-
getNumericValue
public static int getNumericValue(int codePoint) Returns theint
value that the specified character (Unicode code point) represents. For example, the character'\u216C'
(the Roman numeral fifty) will return anint
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 thesechar
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 but the value can not be represented as a nonnegativeint
value; -1 if the character has no numeric value. - Since:
- 1.5
- See Also:
-
isSpace
Deprecated.Replaced by isWhitespace(char).Determines if the specified character is ISO-LATIN-1 white space. This method returnstrue
for the following five characters only:Character Code Name '\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.- See Also:
-
isSpaceChar
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.- Since:
- 1.1
- See Also:
-
-
isSpaceChar
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.- Since:
- 1.5
- See Also:
-
isWhitespace
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
, orPARAGRAPH_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.- Since:
- 1.1
- See Also:
- It is a Unicode space character (
-
isWhitespace
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
, orPARAGRAPH_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.- Since:
- 1.5
- See Also:
- It is a Unicode space character (
-
isISOControl
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.- Since:
- 1.1
- See Also:
-
isISOControl
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.- Since:
- 1.5
- See Also:
-
getType
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. - Since:
- 1.1
- See Also:
-
getType
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. - Since:
- 1.5
- See Also:
-
forDigit
public static char forDigit(int digit, int radix) Determines the character representation for a specific digit in the specified radix. If the value ofradix
is not a valid radix, or the value ofdigit
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 toMIN_RADIX
and less than or equal toMAX_RADIX
. Thedigit
argument is valid if0 <= 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. - See Also:
-
getDirectionality
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 undefinedchar
values isDIRECTIONALITY_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. - Since:
- 1.4
- See Also:
-
getDirectionality
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 isDIRECTIONALITY_UNDEFINED
.- Parameters:
codePoint
- the character (Unicode code point) for which the directionality property is requested.- Returns:
- the directionality property of the character.
- Since:
- 1.5
- See Also:
-
isMirrored
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 thechar
is not mirrored or is not defined.- Since:
- 1.4
-
isMirrored
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.- Since:
- 1.5
-
compareTo
Compares twoCharacter
objects numerically.- Specified by:
compareTo
in interfaceComparable<Character>
- Parameters:
anotherCharacter
- theCharacter
to be compared.- Returns:
- the value
0
if the argumentCharacter
is equal to thisCharacter
; a value less than0
if thisCharacter
is numerically less than theCharacter
argument; and a value greater than0
if thisCharacter
is numerically greater than theCharacter
argument (unsigned comparison). Note that this is strictly a numerical comparison; it is not locale-dependent. - Since:
- 1.2
-
compare
public static int compare(char x, char y) Compares twochar
values numerically. The value returned is identical to what would be returned by:Character.valueOf(x).compareTo(Character.valueOf(y))
- Parameters:
x
- the firstchar
to comparey
- the secondchar
to compare- Returns:
- the value
0
ifx == y
; a value less than0
ifx < y
; and a value greater than0
ifx > y
- Since:
- 1.7
-
reverseBytes
public static char reverseBytes(char ch) Returns the value obtained by reversing the order of the bytes in the specifiedchar
value.- Parameters:
ch
- Thechar
of which to reverse the byte order.- Returns:
- the value obtained by reversing (or, equivalently, swapping)
the bytes in the specified
char
value. - Since:
- 1.5
-
getName
Returns the name of the specified charactercodePoint
, or null if the code point isunassigned
.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 the expression:
For theCharacter.UnicodeBlock.of(codePoint).toString().replace('_', ' ') + " " + Integer.toHexString(codePoint).toUpperCase(Locale.ROOT);
codePoint
s in the UnicodeData file, the name returned by this method follows the naming scheme in the "Unicode Name Property" section of the Unicode Standard. For other code points, such as Hangul/Ideographs, The name generation rule above differs from the one defined in the Unicode Standard.- Parameters:
codePoint
- the character (Unicode code point)- Returns:
- the name of the specified character, or null if the code point is unassigned.
- Throws:
IllegalArgumentException
- if the specifiedcodePoint
is not a valid Unicode code point.- Since:
- 1.7
-
codePointOf
Returns the code point value of the Unicode character specified by the given character name.If a character is not assigned a name by the UnicodeData file (part of the Unicode Character Database maintained by the Unicode Consortium), its name is defined as the result of the expression:
Character.UnicodeBlock.of(codePoint).toString().replace('_', ' ') + " " + Integer.toHexString(codePoint).toUpperCase(Locale.ROOT);
The
name
matching is case insensitive, with any leading and trailing whitespace character removed. For the code points in the UnicodeData file, this method recognizes the name which conforms to the name defined in the "Unicode Name Property" section in the Unicode Standard. For other code points, this method recognizes the name generated withgetName(int)
method.- Parameters:
name
- the character name- Returns:
- the code point value of the character specified by its name.
- Throws:
IllegalArgumentException
- if the specifiedname
is not a valid character name.NullPointerException
- ifname
isnull
- Since:
- 9
-