Class Character
- All Implemented Interfaces:
Serializable,Comparable<Character>,Constable
Character class is thewrapper class for values of the primitivetypechar. An object of typeCharacter contains asingle field whose type ischar.In addition, this class provides a large number of static methods fordetermining a character's category (lowercase letter, digit, etc.)and for converting characters from uppercase to lowercase and viceversa.
Unicode Conformance
The fields and methods of classCharacter are defined in termsof character information from the Unicode Standard, specifically theUnicodeData file that is part of the Unicode Character Database.This file specifies properties including name and category for everyassigned Unicode code point or character range. The file is availablefrom the Unicode Consortium athttp://www.unicode.org.
Character information is based on the Unicode Standard, version 16.0.
The Java platform has supported different versions of the UnicodeStandard over time. Upgrades to newer versions of the Unicode Standardoccurred in the following Java releases, each indicating the new version:
| Java release | Unicode version |
|---|---|
| Java SE 24 | Unicode 16.0 |
| 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
Thechar data type (and therefore the value that aCharacter object encapsulates) are based on theoriginal Unicode specification, which defined characters asfixed-width 16-bit entities. The Unicode Standard has since beenchanged to allow for characters whose representation requires morethan 16 bits. The range of legalcode points is nowU+0000 to U+10FFFF, known asUnicode scalar value.(Refer to thedefinition of the U+n notation in the UnicodeStandard.)
The set of characters from U+0000 to U+FFFF issometimes referred to as theBasic Multilingual Plane (BMP).Characters whose code points are greaterthan U+FFFF are calledsupplementary characters. The Javaplatform uses the UTF-16 representation inchar arrays andin theString andStringBuffer classes. Inthis representation, supplementary characters are represented as a pairofchar values, the first from thehigh-surrogatesrange, (\uD800-\uDBFF), the second from thelow-surrogates range (\uDC00-\uDFFF).
Achar value, therefore, represents BasicMultilingual Plane (BMP) code points, including the surrogatecode points, or code units of the UTF-16 encoding. Anint value represents all Unicode code points,including supplementary code points. The lower (least significant)21 bits ofint are used to represent Unicode codepoints and the upper (most significant) 11 bits must be zero.Unless otherwise specified, the behavior with respect tosupplementary characters and surrogatechar values isas follows:
- The methods that only accept a
charvalue cannot supportsupplementary characters. They treatcharvalues from thesurrogate ranges as undefined characters. For example,Character.isLetter('\uD840')returnsfalse, even thoughthis specific value if followed by any low-surrogate value in a stringwould represent a letter. - The methods that accept an
intvalue support allUnicode characters, including supplementary characters. Forexample,Character.isLetter(0x2F81A)returnstruebecause the code point value represents a letter(a CJK ideograph).
In the Java SE API documentation,Unicode code point isused for character values in the range between U+0000 and U+10FFFF,andUnicode code unit is used for 16-bitchar values that are code units of theUTF-16encoding. For more information on Unicode terminology, refer to theUnicode Glossary.
This is avalue-basedclass; programmers should treat instances that areequal as interchangeable and should notuse instances for synchronization, or unpredictable behavior mayoccur. For example, in a future release, synchronization may fail.
- Since:
- 1.0
- External Specifications
- See Also:
Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionstatic classInstances of this class represent particular subsets of the Unicodecharacter set.static final classA family of character subsets representing the character blocks in theUnicode specification.static enumA family of character subsets representing the character scriptsdefined in theUnicode Standard Annex #24: Script Names.Field Summary
FieldsModifier and TypeFieldDescriptionstatic final intThe number of bytes used to represent acharvalue in unsignedbinary form.static final byteGeneral category "Mc" in the Unicode specification.static final byteGeneral category "Pc" in the Unicode specification.static final byteGeneral category "Cc" in the Unicode specification.static final byteGeneral category "Sc" in the Unicode specification.static final byteGeneral category "Pd" in the Unicode specification.static final byteGeneral category "Nd" in the Unicode specification.static final byteWeak bidirectional character type "AN" in the Unicode specification.static final byteWeak bidirectional character type "BN" in the Unicode specification.static final byteWeak bidirectional character type "CS" in the Unicode specification.static final byteWeak bidirectional character type "EN" in the Unicode specification.static final byteWeak bidirectional character type "ES" in the Unicode specification.static final byteWeak bidirectional character type "ET" in the Unicode specification.static final byteWeak bidirectional character type "FSI" in the Unicode specification.static final byteStrong bidirectional character type "L" in the Unicode specification.static final byteStrong bidirectional character type "LRE" in the Unicode specification.static final byteWeak bidirectional character type "LRI" in the Unicode specification.static final byteStrong bidirectional character type "LRO" in the Unicode specification.static final byteWeak bidirectional character type "NSM" in the Unicode specification.static final byteNeutral bidirectional character type "ON" in the Unicode specification.static final byteNeutral bidirectional character type "B" in the Unicode specification.static final byteWeak bidirectional character type "PDF" in the Unicode specification.static final byteWeak bidirectional character type "PDI" in the Unicode specification.static final byteStrong bidirectional character type "R" in the Unicode specification.static final byteStrong bidirectional character type "AL" in the Unicode specification.static final byteStrong bidirectional character type "RLE" in the Unicode specification.static final byteWeak bidirectional character type "RLI" in the Unicode specification.static final byteStrong bidirectional character type "RLO" in the Unicode specification.static final byteNeutral bidirectional character type "S" in the Unicode specification.static final byteUndefined bidirectional character type.static final byteNeutral bidirectional character type "WS" in the Unicode specification.static final byteGeneral category "Me" in the Unicode specification.static final byteGeneral category "Pe" in the Unicode specification.static final byteGeneral category "Pf" in the Unicode specification.static final byteGeneral category "Cf" in the Unicode specification.static final byteGeneral category "Pi" in the Unicode specification.static final byteGeneral category "Nl" in the Unicode specification.static final byteGeneral category "Zl" in the Unicode specification.static final byteGeneral category "Ll" in the Unicode specification.static final byteGeneral category "Sm" in the Unicode specification.static final intThe maximum value of aUnicode code point, constantU+10FFFF.static final charThe maximum value of aUnicode high-surrogate code unitin the UTF-16 encoding, constant'\uDBFF'.static final charThe maximum value of aUnicode low-surrogate code unitin the UTF-16 encoding, constant'\uDFFF'.static final intThe maximum radix available for conversion to and from strings.static final charThe maximum value of a Unicode surrogate code unit in theUTF-16 encoding, constant'\uDFFF'.static final charThe constant value of this field is the largest value of typechar,'\uFFFF'.static final intThe minimum value of aUnicode code point, constantU+0000.static final charThe minimum value of aUnicode high-surrogate code unitin the UTF-16 encoding, constant'\uD800'.static final charThe minimum value of aUnicode low-surrogate code unitin the UTF-16 encoding, constant'\uDC00'.static final intThe minimum radix available for conversion to and from strings.static final intThe minimum value of aUnicode supplementary code point, constantU+10000.static final charThe minimum value of a Unicode surrogate code unit in theUTF-16 encoding, constant'\uD800'.static final charThe constant value of this field is the smallest value of typechar,'\u0000'.static final byteGeneral category "Lm" in the Unicode specification.static final byteGeneral category "Sk" in the Unicode specification.static final byteGeneral category "Mn" in the Unicode specification.static final byteGeneral category "Lo" in the Unicode specification.static final byteGeneral category "No" in the Unicode specification.static final byteGeneral category "Po" in the Unicode specification.static final byteGeneral category "So" in the Unicode specification.static final byteGeneral category "Zp" in the Unicode specification.static final byteGeneral category "Co" in the Unicode specification.static final intThe number of bits used to represent acharvalue in unsignedbinary form, constant16.static final byteGeneral category "Zs" in the Unicode specification.static final byteGeneral category "Ps" in the Unicode specification.static final byteGeneral category "Cs" in the Unicode specification.static final byteGeneral category "Lt" in the Unicode specification.TheClassinstance representing the primitive typechar.static final byteGeneral category "Cn" in the Unicode specification.static final byteGeneral category "Lu" in the Unicode specification.Constructor Summary
ConstructorsConstructorDescriptionCharacter(char value) Deprecated.It is rarely appropriate to use this constructor.Method Summary
Modifier and TypeMethodDescriptionstatic intcharCount(int codePoint) Determines the number ofcharvalues needed torepresent the specified character (Unicode code point).charReturns the value of thisCharacterobject.static intcodePointAt(char[] a, int index) Returns the code point at the given index of thechararray.static intcodePointAt(char[] a, int index, int limit) Returns the code point at the given index of thechararray, where only array elements withindexless thanlimitcan be used.static intcodePointAt(CharSequence seq, int index) Returns the code point at the given index of theCharSequence.static intcodePointBefore(char[] a, int index) Returns the code point preceding the given index of thechararray.static intcodePointBefore(char[] a, int index, int start) Returns the code point preceding the given index of thechararray, where only array elements withindexgreater than or equal tostartcan be used.static intcodePointBefore(CharSequence seq, int index) Returns the code point preceding the given index of theCharSequence.static intcodePointCount(char[] a, int offset, int count) Returns the number of Unicode code points in a subarray of thechararray argument.static intcodePointCount(CharSequence seq, int beginIndex, int endIndex) Returns the number of Unicode code points in the text range ofthe specified char sequence.static intcodePointOf(String name) Returns the code point value of the Unicode character specified bythe given character name.static intcompare(char x, char y) Compares twocharvalues numerically.intCompares twoCharacterobjects numerically.Returns anOptionalcontaining the nominal descriptor for thisinstance.static intdigit(char ch, int radix) Returns the numeric value of the characterchin thespecified radix.static intdigit(int codePoint, int radix) Returns the numeric value of the specified character (Unicodecode point) in the specified radix.booleanCompares this object against the specified object.static charforDigit(int digit, int radix) Determines the character representation for a specific digit inthe specified radix.static bytegetDirectionality(char ch) Returns the Unicode directionality property for the givencharacter.static bytegetDirectionality(int codePoint) Returns the Unicode directionality property for the givencharacter (Unicode code point).staticStringgetName(int codePoint) Returns the name of the specified charactercodePoint, or null if the code point isunassigned.static intgetNumericValue(char ch) Returns theintvalue that the specified Unicodecharacter represents.static intgetNumericValue(int codePoint) Returns theintvalue that the specifiedcharacter (Unicode code point) represents.static intgetType(char ch) Returns a value indicating a character's general category.static intgetType(int codePoint) Returns a value indicating a character's general category.inthashCode()Returns a hash code for thisCharacter; equal to the resultof invokingcharValue().static inthashCode(char value) Returns a hash code for acharvalue; compatible withCharacter.hashCode().static charhighSurrogate(int codePoint) Returns the leading surrogate (ahigh surrogate code unit) of thesurrogate pairrepresenting the specified supplementary character (Unicodecode point) in the UTF-16 encoding.static booleanisAlphabetic(int codePoint) Determines if the specified character (Unicode code point) is alphabetic.static booleanisBmpCodePoint(int codePoint) Determines whether the specified character (Unicode code point)is in theBasic Multilingual Plane (BMP).static booleanisDefined(char ch) Determines if a character is defined in Unicode.static booleanisDefined(int codePoint) Determines if a character (Unicode code point) is defined in Unicode.static booleanisDigit(char ch) Determines if the specified character is a digit.static booleanisDigit(int codePoint) Determines if the specified character (Unicode code point) is a digit.static booleanisEmoji(int codePoint) Determines if the specified character (Unicode code point) is an Emoji.static booleanisEmojiComponent(int codePoint) Determines if the specified character (Unicode code point) is anEmoji Component.static booleanisEmojiModifier(int codePoint) Determines if the specified character (Unicode code point) is anEmoji Modifier.static booleanisEmojiModifierBase(int codePoint) Determines if the specified character (Unicode code point) is anEmoji Modifier Base.static booleanisEmojiPresentation(int codePoint) Determines if the specified character (Unicode code point) has theEmoji Presentation property by default.static booleanisExtendedPictographic(int codePoint) Determines if the specified character (Unicode code point) isan Extended Pictographic.static booleanisHighSurrogate(char ch) Determines if the givencharvalue is aUnicode high-surrogate code unit(also known asleading-surrogate code unit).static booleanisIdentifierIgnorable(char ch) Determines if the specified character should be regarded asan ignorable character in a Java identifier or a Unicode identifier.static booleanisIdentifierIgnorable(int codePoint) Determines if the specified character (Unicode code point) should be regarded asan ignorable character in a Java identifier or a Unicode identifier.static booleanisIdeographic(int codePoint) Determines if the specified character (Unicode code point) is a CJKV(Chinese, Japanese, Korean and Vietnamese) ideograph, as defined bythe Unicode Standard.static booleanisISOControl(char ch) Determines if the specified character is an ISO controlcharacter.static booleanisISOControl(int codePoint) Determines if the referenced character (Unicode code point) is an ISO controlcharacter.static booleanisJavaIdentifierPart(char ch) Determines if the specified character may be part of a Javaidentifier as other than the first character.static booleanisJavaIdentifierPart(int codePoint) Determines if the character (Unicode code point) may be part of a Javaidentifier as other than the first character.static booleanisJavaIdentifierStart(char ch) Determines if the specified character ispermissible as the first character in a Java identifier.static booleanisJavaIdentifierStart(int codePoint) Determines if the character (Unicode code point) ispermissible as the first character in a Java identifier.static booleanisJavaLetter(char ch) Deprecated.Replaced by isJavaIdentifierStart(char).static booleanisJavaLetterOrDigit(char ch) Deprecated.Replaced by isJavaIdentifierPart(char).static booleanisLetter(char ch) Determines if the specified character is a letter.static booleanisLetter(int codePoint) Determines if the specified character (Unicode code point) is a letter.static booleanisLetterOrDigit(char ch) Determines if the specified character is a letter or digit.static booleanisLetterOrDigit(int codePoint) Determines if the specified character (Unicode code point) is a letter or digit.static booleanisLowerCase(char ch) Determines if the specified character is a lowercase character.static booleanisLowerCase(int codePoint) Determines if the specified character (Unicode code point) is alowercase character.static booleanisLowSurrogate(char ch) Determines if the givencharvalue is aUnicode low-surrogate code unit(also known astrailing-surrogate code unit).static booleanisMirrored(char ch) Determines whether the character is mirrored according to theUnicode specification.static booleanisMirrored(int codePoint) Determines whether the specified character (Unicode code point)is mirrored according to the Unicode specification.static booleanisSpace(char ch) Deprecated.Replaced by isWhitespace(char).static booleanisSpaceChar(char ch) Determines if the specified character is a Unicode space character.static booleanisSpaceChar(int codePoint) Determines if the specified character (Unicode code point) is aUnicode space character.static booleanisSupplementaryCodePoint(int codePoint) Determines whether the specified character (Unicode code point)is in thesupplementary character range.static booleanisSurrogate(char ch) Determines if the givencharvalue is a Unicodesurrogate code unit.static booleanisSurrogatePair(char high, char low) Determines whether the specified pair ofcharvalues is a validUnicode surrogate pair.static booleanisTitleCase(char ch) Determines if the specified character is a titlecase character.static booleanisTitleCase(int codePoint) Determines if the specified character (Unicode code point) is a titlecase character.static booleanisUnicodeIdentifierPart(char ch) Determines if the specified character may be part of a Unicodeidentifier as other than the first character.static booleanisUnicodeIdentifierPart(int codePoint) Determines if the specified character (Unicode code point) may be part of a Unicodeidentifier as other than the first character.static booleanisUnicodeIdentifierStart(char ch) Determines if the specified character is permissible as thefirst character in a Unicode identifier.static booleanisUnicodeIdentifierStart(int codePoint) Determines if the specified character (Unicode code point) is permissible as thefirst character in a Unicode identifier.static booleanisUpperCase(char ch) Determines if the specified character is an uppercase character.static booleanisUpperCase(int codePoint) Determines if the specified character (Unicode code point) is an uppercase character.static booleanisValidCodePoint(int codePoint) Determines whether the specified code point is a validUnicode code point value.static booleanisWhitespace(char ch) Determines if the specified character is white space according to Java.static booleanisWhitespace(int codePoint) Determines if the specified character (Unicode code point) iswhite space according to Java.static charlowSurrogate(int codePoint) Returns the trailing surrogate (alow surrogate code unit) of thesurrogate pairrepresenting the specified supplementary character (Unicodecode point) in the UTF-16 encoding.static intoffsetByCodePoints(char[] a, int start, int count, int index, int codePointOffset) Returns the index within the givencharsubarraythat is offset from the givenindexbycodePointOffsetcode points.static intoffsetByCodePoints(CharSequence seq, int index, int codePointOffset) Returns the index within the given char sequence that is offsetfrom the givenindexbycodePointOffsetcode points.static charreverseBytes(char ch) Returns the value obtained by reversing the order of the bytes in thespecifiedcharvalue.static char[]toChars(int codePoint) Converts the specified character (Unicode code point) to itsUTF-16 representation stored in achararray.static inttoChars(int codePoint, char[] dst, int dstIndex) Converts the specified character (Unicode code point) to itsUTF-16 representation.static inttoCodePoint(char high, char low) Converts the specified surrogate pair to its supplementary codepoint value.static chartoLowerCase(char ch) Converts the character argument to lowercase using casemapping information from the UnicodeData file.static inttoLowerCase(int codePoint) Converts the character (Unicode code point) argument tolowercase using case mapping information from the UnicodeDatafile.toString()Returns aStringobject representing thisCharacter's value.staticStringtoString(char c) Returns aStringobject representing thespecifiedchar.staticStringtoString(int codePoint) Returns aStringobject representing thespecified character (Unicode code point).static chartoTitleCase(char ch) Converts the character argument to titlecase using case mappinginformation from the UnicodeData file.static inttoTitleCase(int codePoint) Converts the character (Unicode code point) argument to titlecase using case mappinginformation from the UnicodeData file.static chartoUpperCase(char ch) Converts the character argument to uppercase using case mappinginformation from the UnicodeData file.static inttoUpperCase(int codePoint) Converts the character (Unicode code point) argument touppercase using case mapping information from the UnicodeDatafile.staticCharactervalueOf(char c) Returns aCharacterinstance representing the specifiedcharvalue.
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 permittedfor the radix argument in radix-conversion methods such as thedigitmethod, theforDigitmethod, and thetoStringmethod of classInteger.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 permittedfor the radix argument in radix-conversion methods such as thedigitmethod, theforDigitmethod, and thetoStringmethod of classInteger.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. Undefinedcharvalues 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 aUnicode high-surrogate code unitin the UTF-16 encoding, constant'\uD800'.A high-surrogate is also known as aleading-surrogate.- Since:
- 1.5
- See Also:
MAX_HIGH_SURROGATE
public static final char MAX_HIGH_SURROGATEThe maximum value of aUnicode high-surrogate code unitin the UTF-16 encoding, constant'\uDBFF'.A high-surrogate is also known as aleading-surrogate.- Since:
- 1.5
- See Also:
MIN_LOW_SURROGATE
public static final char MIN_LOW_SURROGATEThe minimum value of aUnicode low-surrogate code unitin the UTF-16 encoding, constant'\uDC00'.A low-surrogate is also known as atrailing-surrogate.- Since:
- 1.5
- See Also:
MAX_LOW_SURROGATE
public static final char MAX_LOW_SURROGATEThe maximum value of aUnicode low-surrogate code unitin the UTF-16 encoding, constant'\uDFFF'.A low-surrogate is also known as atrailing-surrogate.- Since:
- 1.5
- See Also:
MIN_SURROGATE
public static final char MIN_SURROGATEThe minimum value of a Unicode surrogate code unit in theUTF-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 theUTF-16 encoding, constant'\uDFFF'.- Since:
- 1.5
- See Also:
MIN_SUPPLEMENTARY_CODE_POINT
public static final int MIN_SUPPLEMENTARY_CODE_POINTThe minimum value of aUnicode supplementary code point, constantU+10000.- Since:
- 1.5
- See Also:
MIN_CODE_POINT
public static final int MIN_CODE_POINTThe minimum value of aUnicode code point, constantU+0000.- Since:
- 1.5
- See Also:
MAX_CODE_POINT
public static final int MAX_CODE_POINTThe maximum value of aUnicode code point, constantU+10FFFF.- Since:
- 1.5
- See Also:
SIZE
public static final int SIZEThe number of bits used to represent acharvalue in unsignedbinary form, constant16.- Since:
- 1.5
- See Also:
BYTES
public static final int BYTESThe number of bytes used to represent acharvalue in unsignedbinary form.- Since:
- 1.8
- See Also:
Constructor Details
Character
Deprecated.It is rarely appropriate to use this constructor. The static factoryvalueOf(char)is generally a better choice, as it islikely to yield significantly better space and time performance.Constructs a newly allocatedCharacterobject thatrepresents the specifiedcharvalue.- Parameters:
value- the value to be represented by theCharacterobject.
Method Details
describeConstable
Returns anOptionalcontaining the nominal descriptor for thisinstance.- Specified by:
describeConstablein interfaceConstable- Returns:
- an
Optionaldescribing theCharacter instance - Since:
- 15
valueOf
Returns aCharacterinstance representing the specifiedcharvalue.If a newCharacterinstance is not required, this methodshould generally be used in preference to the constructorCharacter(char), as this method is likely to yieldsignificantly better space and time performance by cachingfrequently requested values.This method will always cache values in the range'\u0000'to'\u007F', inclusive, and maycache other values outside of this range.- Parameters:
c- a char value.- Returns:
- a
Characterinstance representingc. - Since:
- 1.5
charValue
public char charValue()Returns the value of thisCharacterobject.- Returns:
- the primitive
charvalue represented by this object.
hashCode
hashCode
public static int hashCode(char value) Returns a hash code for acharvalue; compatible withCharacter.hashCode().- Parameters:
value- Thecharfor which to return a hash code.- Returns:
- a hash code value for a
charvalue. - Since:
- 1.8
equals
Compares this object against the specified object.The result istrueif and only if the argument is notnulland is aCharacterobject thatrepresents the samecharvalue as this object.toString
toString
Returns aStringobject representing thespecifiedchar. The result is a string of length1 consisting solely of the specifiedchar.- API Note:
- This method cannot handle supplementary characters. To supportall Unicode characters, including supplementary characters, usethe
toString(int)method. - Parameters:
c- thecharto be converted- Returns:
- the string representation of the specified
char - Since:
- 1.4
toString
Returns aStringobject representing thespecified character (Unicode code point). The result is a string oflength 1 or 2, consisting solely of the specifiedcodePoint.- Parameters:
codePoint- thecodePointto be converted- Returns:
- the string representation of the specified
codePoint - Throws:
IllegalArgumentException- if the specifiedcodePointis not avalid Unicode code point.- Since:
- 11
isValidCodePoint
public static boolean isValidCodePoint(int codePoint) Determines whether the specified code point is a validUnicode code point value.- Parameters:
codePoint- the Unicode code point to be tested- Returns:
trueif the specified code point value is betweenMIN_CODE_POINTandMAX_CODE_POINTinclusive;falseotherwise.- Since:
- 1.5
isBmpCodePoint
public static boolean isBmpCodePoint(int codePoint) Determines whether the specified character (Unicode code point)is in theBasic 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 thesupplementary character range.- Parameters:
codePoint- the character (Unicode code point) to be tested- Returns:
trueif the specified code point is betweenMIN_SUPPLEMENTARY_CODE_POINTandMAX_CODE_POINTinclusive;falseotherwise.- Since:
- 1.5
isHighSurrogate
public static boolean isHighSurrogate(char ch) Determines if the givencharvalue is aUnicode high-surrogate code unit(also known asleading-surrogate code unit).Such values do not represent characters by themselves,but are used in the representation ofsupplementary charactersin the UTF-16 encoding.
- Parameters:
ch- thecharvalue to be tested.- Returns:
trueif thecharvalue is betweenMIN_HIGH_SURROGATEandMAX_HIGH_SURROGATEinclusive;falseotherwise.- Since:
- 1.5
- See Also:
isLowSurrogate
public static boolean isLowSurrogate(char ch) Determines if the givencharvalue is aUnicode low-surrogate code unit(also known astrailing-surrogate code unit).Such values do not represent characters by themselves,but are used in the representation ofsupplementary charactersin the UTF-16 encoding.
- Parameters:
ch- thecharvalue to be tested.- Returns:
trueif thecharvalue is betweenMIN_LOW_SURROGATEandMAX_LOW_SURROGATEinclusive;falseotherwise.- Since:
- 1.5
- See Also:
isSurrogate
public static boolean isSurrogate(char ch) Determines if the givencharvalue is a Unicodesurrogate code unit.Such values do not represent characters by themselves,but are used in the representation ofsupplementary charactersin the UTF-16 encoding.
A char value is a surrogate code unit if and only if it is eitheralow-surrogate code unit orahigh-surrogate code unit.
- Parameters:
ch- thecharvalue to be tested.- Returns:
trueif thecharvalue is betweenMIN_SURROGATEandMAX_SURROGATEinclusive;falseotherwise.- Since:
- 1.7
isSurrogatePair
public static boolean isSurrogatePair(char high, char low) Determines whether the specified pair ofcharvalues is a validUnicode 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:
trueif the specified high andlow-surrogate code values represent a valid surrogate pair;falseotherwise.- Since:
- 1.5
charCount
public static int charCount(int codePoint) Determines the number ofcharvalues needed torepresent the specified character (Unicode code point). If thespecified character is equal to or greater than 0x10000, thenthe method returns 2. Otherwise, the method returns 1.This method doesn't validate the specified character to be avalid Unicode code point. The caller must validate thecharacter value using
isValidCodePointif 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 codepoint value. This method does not validate the specifiedsurrogate pair. The caller must validate it usingisSurrogatePairif 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 thecharvalue atthe given index in theCharSequenceis in thehigh-surrogate range, the following index is less than thelength of theCharSequence, and thecharvalue at the following index is in thelow-surrogate range, then the supplementary code pointcorresponding to this surrogate pair is returned. Otherwise,thecharvalue at the given index is returned.- Parameters:
seq- a sequence ofcharvalues (Unicode codeunits)index- the index to thecharvalues (Unicodecode units) inseqto be converted- Returns:
- the Unicode code point at the given index
- Throws:
NullPointerException- ifseqis null.IndexOutOfBoundsException- if the valueindexis 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 thechararray. If thecharvalue atthe given index in thechararray is in thehigh-surrogate range, the following index is less than thelength of thechararray, and thecharvalue at the following index is in thelow-surrogate range, then the supplementary code pointcorresponding to this surrogate pair is returned. Otherwise,thecharvalue at the given index is returned.- Parameters:
a- thechararrayindex- the index to thecharvalues (Unicodecode units) in thechararray to be converted- Returns:
- the Unicode code point at the given index
- Throws:
NullPointerException- ifais null.IndexOutOfBoundsException- if the valueindexis negative or not less thanthe length of thechararray.- Since:
- 1.5
codePointAt
public static int codePointAt(char[] a, int index, int limit) Returns the code point at the given index of thechararray, where only array elements withindexless thanlimitcan be used. Ifthecharvalue at the given index in thechararray is in the high-surrogate range, thefollowing index is less than thelimit, and thecharvalue at the following index is in thelow-surrogate range, then the supplementary code pointcorresponding to this surrogate pair is returned. Otherwise,thecharvalue at the given index is returned.- Parameters:
a- thechararrayindex- the index to thecharvalues (Unicodecode units) in thechararray to be convertedlimit- the index after the last array element thatcan be used in thechararray- Returns:
- the Unicode code point at the given index
- Throws:
NullPointerException- ifais null.IndexOutOfBoundsException- if theindexargument is negative or not less than thelimitargument, or if thelimitargument is negative orgreater than the length of thechararray.- Since:
- 1.5
codePointBefore
Returns the code point preceding the given index of theCharSequence. If thecharvalue at(index - 1)in theCharSequenceis inthe low-surrogate range,(index - 2)is notnegative, and thecharvalue at(index - 2)in theCharSequenceis in thehigh-surrogate range, then the supplementary code pointcorresponding to this surrogate pair is returned. Otherwise,thecharvalue at(index - 1)isreturned.- Parameters:
seq- theCharSequenceinstanceindex- the index following the code point that should be returned- Returns:
- the Unicode code point value before the given index.
- Throws:
NullPointerException- ifseqis null.IndexOutOfBoundsException- if theindexargument 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 thechararray. If thecharvalue at(index - 1)in thechararray is inthe low-surrogate range,(index - 2)is notnegative, and thecharvalue at(index - 2)in thechararray is in thehigh-surrogate range, then the supplementary code pointcorresponding to this surrogate pair is returned. Otherwise,thecharvalue at(index - 1)isreturned.- Parameters:
a- thechararrayindex- the index following the code point that should be returned- Returns:
- the Unicode code point value before the given index.
- Throws:
NullPointerException- ifais null.IndexOutOfBoundsException- if theindexargument is less than 1 or greater than the length of thechararray- Since:
- 1.5
codePointBefore
public static int codePointBefore(char[] a, int index, int start) Returns the code point preceding the given index of thechararray, where only array elements withindexgreater than or equal tostartcan be used. If thecharvalue at(index - 1)in thechararray is in thelow-surrogate range,(index - 2)is not less thanstart, and thecharvalue at(index - 2)in thechararray is inthe high-surrogate range, then the supplementary code pointcorresponding to this surrogate pair is returned. Otherwise,thecharvalue at(index - 1)isreturned.- Parameters:
a- thechararrayindex- the index following the code point that should be returnedstart- the index of the first array element in thechararray- Returns:
- the Unicode code point value before the given index.
- Throws:
NullPointerException- ifais null.IndexOutOfBoundsException- if theindexargument is not greater than thestartargument oris greater than the length of thechararray, orif thestartargument is negative or not less thanthe length of thechararray.- Since:
- 1.5
highSurrogate
public static char highSurrogate(int codePoint) Returns the leading surrogate (ahigh surrogate code unit) of thesurrogate pairrepresenting the specified supplementary character (Unicodecode point) in the UTF-16 encoding. If the specified characteris not asupplementary character,an unspecifiedcharis returned.If
isSupplementaryCodePoint(x)istrue, thenisHighSurrogate(highSurrogate(x))andtoCodePoint(highSurrogate(x),lowSurrogate(x)) == xare 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 (alow surrogate code unit) of thesurrogate pairrepresenting the specified supplementary character (Unicodecode point) in the UTF-16 encoding. If the specified characteris not asupplementary character,an unspecifiedcharis returned.If
isSupplementaryCodePoint(x)istrue, thenisLowSurrogate(lowSurrogate(x))andtoCodePoint(highSurrogate(x), lowSurrogate(x)) == xare 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 itsUTF-16 representation. If the specified code point is a BMP(Basic Multilingual Plane or Plane 0) value, the same value isstored indst[dstIndex], and 1 is returned. If thespecified code point is a supplementary character, itssurrogate 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 ofcharin which thecodePoint's UTF-16 value is stored.dstIndex- the start index into thedstarray where the converted value is stored.- Returns:
- 1 if the code point is a BMP code point, 2 if thecode point is a supplementary code point.
- Throws:
IllegalArgumentException- if the specifiedcodePointis not a valid Unicode code point.NullPointerException- if the specifieddstis null.IndexOutOfBoundsException- ifdstIndexis negative or not less thandst.length, or ifdstatdstIndexdoesn't have enougharray element(s) to store the resultingcharvalue(s). (IfdstIndexis equal todst.length-1and the specifiedcodePointis a supplementary character, thehigh-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 itsUTF-16 representation stored in achararray. Ifthe specified code point is a BMP (Basic Multilingual Plane orPlane 0) value, the resultingchararray hasthe same value ascodePoint. If the specified codepoint is a supplementary code point, the resultingchararray has the corresponding surrogate pair.- Parameters:
codePoint- a Unicode code point- Returns:
- a
chararray havingcodePoint's UTF-16 representation. - Throws:
IllegalArgumentException- if the specifiedcodePointis not a valid Unicode code point.- Since:
- 1.5
codePointCount
Returns the number of Unicode code points in the text range ofthe specified char sequence. The text range begins at thespecifiedbeginIndexand extends to thecharat indexendIndex - 1. Thus thelength (inchars) of the text range isendIndex-beginIndex. Unpaired surrogates withinthe text range count as one code point each.- Parameters:
seq- the char sequencebeginIndex- the index to the firstcharofthe text range.endIndex- the index after the lastcharofthe text range.- Returns:
- the number of Unicode code points in the specified textrange
- Throws:
NullPointerException- ifseqis null.IndexOutOfBoundsException- if thebeginIndexis negative, orendIndexis larger than the length of the given sequence, orbeginIndexis 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 thechararray argument. Theoffsetargument is the index of the firstcharof thesubarray and thecountargument specifies thelength of the subarray inchars. Unpairedsurrogates within the subarray count as one code point each.- Parameters:
a- thechararrayoffset- the index of the firstcharin thegivenchararraycount- the length of the subarray inchars- Returns:
- the number of Unicode code points in the specified subarray
- Throws:
NullPointerException- ifais null.IndexOutOfBoundsException- ifoffsetorcountis negative, or ifoffset +countis larger than the length of the given array.- Since:
- 1.5
offsetByCodePoints
Returns the index within the given char sequence that is offsetfrom the givenindexbycodePointOffsetcode points. Unpaired surrogates within the text range given byindexandcodePointOffsetcount asone 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- ifseqis null.IndexOutOfBoundsException- ifindexis negative or larger than the length of the char sequence, or ifcodePointOffsetis positive and the subsequence starting withindexhas fewer thancodePointOffsetcode points, or ifcodePointOffsetis negative and the subsequence beforeindexhas fewer than the absolute value ofcodePointOffsetcode points.- Since:
- 1.5
offsetByCodePoints
public static int offsetByCodePoints(char[] a, int start, int count, int index, int codePointOffset) Returns the index within the givencharsubarraythat is offset from the givenindexbycodePointOffsetcode points. Thestartandcountarguments specify asubarray of thechararray. Unpaired surrogateswithin the text range given byindexandcodePointOffsetcount as one code point each.- Parameters:
a- thechararraystart- the index of the firstcharof thesubarraycount- the length of the subarray incharsindex- the index to be offsetcodePointOffset- the offset in code points- Returns:
- the index within the subarray
- Throws:
NullPointerException- ifais null.IndexOutOfBoundsException- ifstartorcountis negative, or ifstart + countis larger than the length of the given array, or ifindexis less thanstartor larger thenstart + count, or ifcodePointOffsetis positive and the text range starting withindexand ending withstart + count - 1has fewer thancodePointOffsetcode points, or ifcodePointOffsetis negative and the text range starting withstartand ending withindex - 1has fewer than the absolute value ofcodePointOffsetcode 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, providedby
Character.getType(ch), isLOWERCASE_LETTER, or it has contributory propertyOther_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 supportall Unicode characters, including supplementary characters, usethe
isLowerCase(int)method.- Parameters:
ch- the character to be tested.- Returns:
trueif the character is lowercase;falseotherwise.- See Also:
isLowerCase
public static boolean isLowerCase(int codePoint) Determines if the specified character (Unicode code point) is alowercase character.A character is lowercase if its general category type, providedby
getType(codePoint), isLOWERCASE_LETTER, or it has contributory propertyOther_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:
trueif the character is lowercase;falseotherwise.- 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 supportall Unicode characters, including supplementary characters, usethe
isUpperCase(int)method.- Parameters:
ch- the character to be tested.- Returns:
trueif the character is uppercase;falseotherwise.- 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:
trueif the character is uppercase;falseotherwise.- 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 generalcategory type, provided by
Character.getType(ch),isTITLECASE_LETTER.Some characters look like pairs of Latin letters. For example, thereis an uppercase letter that looks like "LJ" and has a correspondinglowercase letter that looks like "lj". A third form, which looks like "Lj",is the appropriate form to use when rendering a word in lowercasewith 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 CARONLATIN CAPITAL LETTER L WITH SMALL LETTER JLATIN CAPITAL LETTER N WITH SMALL LETTER JLATIN CAPITAL LETTER D WITH SMALL LETTER Z
Many other Unicode characters are titlecase too.
Note: This method cannot handle supplementary characters. To supportall Unicode characters, including supplementary characters, usethe
isTitleCase(int)method.- Parameters:
ch- the character to be tested.- Returns:
trueif the character is titlecase;falseotherwise.- 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 generalcategory type, provided by
getType(codePoint),isTITLECASE_LETTER.Some characters look like pairs of Latin letters. For example, thereis an uppercase letter that looks like "LJ" and has a correspondinglowercase letter that looks like "lj". A third form, which looks like "Lj",is the appropriate form to use when rendering a word in lowercasewith 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 CARONLATIN CAPITAL LETTER L WITH SMALL LETTER JLATIN CAPITAL LETTER N WITH SMALL LETTER JLATIN 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:
trueif the character is titlecase;falseotherwise.- 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, providedby
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 supportall Unicode characters, including supplementary characters, usethe
isDigit(int)method.- Parameters:
ch- the character to be tested.- Returns:
trueif the character is a digit;falseotherwise.- 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, providedby
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:
trueif the character is a digit;falseotherwise.- 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 supportall Unicode characters, including supplementary characters, usethe
isDefined(int)method.- Parameters:
ch- the character to be tested- Returns:
trueif the character has a defined meaning in Unicode;falseotherwise.- 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:
trueif the character has a defined meaning in Unicode;falseotherwise.- 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 generalcategory type, provided by
Character.getType(ch),is any of the following:UPPERCASE_LETTERLOWERCASE_LETTERTITLECASE_LETTERMODIFIER_LETTEROTHER_LETTER
Note: This method cannot handle supplementary characters. To supportall Unicode characters, including supplementary characters, usethe
isLetter(int)method.- Parameters:
ch- the character to be tested.- Returns:
trueif the character is a letter;falseotherwise.- 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 generalcategory type, provided by
getType(codePoint),is any of the following:UPPERCASE_LETTERLOWERCASE_LETTERTITLECASE_LETTERMODIFIER_LETTEROTHER_LETTER
- Parameters:
codePoint- the character (Unicode code point) to be tested.- Returns:
trueif the character is a letter;falseotherwise.- 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)returnstruefor the character.Note: This method cannot handle supplementary characters. To supportall Unicode characters, including supplementary characters, usethe
isLetterOrDigit(int)method.- Parameters:
ch- the character to be tested.- Returns:
trueif the character is a letter or digit;falseotherwise.- 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)returnstruefor the character.- Parameters:
codePoint- the character (Unicode code point) to be tested.- Returns:
trueif the character is a letter or digit;falseotherwise.- Since:
- 1.5
- See Also:
isJavaLetter
Deprecated.Replaced by isJavaIdentifierStart(char).Determines if the specified character is permissible as the firstcharacter in a Java identifier.A character may start a Java identifier if and only ifone of the following conditions is true:
isLetter(ch)returnstruegetType(ch)returnsLETTER_NUMBERchis a currency symbol (such as'$')chis a connecting punctuation character (such as'_').
- Parameters:
ch- the character to be tested.- Returns:
trueif the character may start a Java identifier;falseotherwise.- Since:
- 1.0.2
- See Also:
isJavaLetterOrDigit
Deprecated.Replaced by isJavaIdentifierPart(char).Determines if the specified character may be part of a Javaidentifier as other than the first character.A character may be part of a Java identifier if and only if oneof the following conditions is true:
- it is a letter
- it is a currency symbol (such as
'$') - 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
isIdentifierIgnorablereturnstruefor the character.
- Parameters:
ch- the character to be tested.- Returns:
trueif the character may be part of a Java identifier;falseotherwise.- 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 ofthe following:UPPERCASE_LETTERLOWERCASE_LETTERTITLECASE_LETTERMODIFIER_LETTEROTHER_LETTERLETTER_NUMBER
- Parameters:
codePoint- the character (Unicode code point) to be tested.- Returns:
trueif the character is a Unicode alphabet character,falseotherwise.- 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 bythe Unicode Standard.- Parameters:
codePoint- the character (Unicode code point) to be tested.- Returns:
trueif the character is a Unicode ideograph character,falseotherwise.- Since:
- 1.7
isJavaIdentifierStart
public static boolean isJavaIdentifierStart(char ch) Determines if the specified character ispermissible as the first character in a Java identifier.A character may start a Java identifier if and only ifone of the following conditions is true:
isLetter(ch)returnstruegetType(ch)returnsLETTER_NUMBERchis a currency symbol (such as'$')chis a connecting punctuation character (such as'_').
Note: This method cannot handle supplementary characters. To supportall Unicode characters, including supplementary characters, usethe
isJavaIdentifierStart(int)method.- Parameters:
ch- the character to be tested.- Returns:
trueif the character may start a Java identifier;falseotherwise.- Since:
- 1.1
- See Also:
isJavaIdentifierStart
public static boolean isJavaIdentifierStart(int codePoint) Determines if the character (Unicode code point) ispermissible as the first character in a Java identifier.A character may start a Java identifier if and only ifone of the following conditions is true:
isLetter(codePoint)returnstruegetType(codePoint)returnsLETTER_NUMBER- the referenced character is a currency symbol (such as
'$') - the referenced character is a connecting punctuation character (such as
'_').
- Parameters:
codePoint- the character (Unicode code point) to be tested.- Returns:
trueif the character may start a Java identifier;falseotherwise.- Since:
- 1.5
- See Also:
isJavaIdentifierPart
public static boolean isJavaIdentifierPart(char ch) Determines if the specified character may be part of a Javaidentifier as other than the first character.A character may be part of a Java identifier if any of the followingconditions are true:
- it is a letter
- it is a currency symbol (such as
'$') - it is a connecting punctuation character (such as
'_') - it is a digit
- it is a numeric letter (such as a Roman numeral character)
- it is a combining mark
- it is a non-spacing mark
isIdentifierIgnorablereturnstruefor the character
Note: This method cannot handle supplementary characters. To supportall Unicode characters, including supplementary characters, usethe
isJavaIdentifierPart(int)method.- Parameters:
ch- the character to be tested.- Returns:
trueif the character may be part of a Java identifier;falseotherwise.- Since:
- 1.1
- See Also:
isJavaIdentifierPart
public static boolean isJavaIdentifierPart(int codePoint) Determines if the character (Unicode code point) may be part of a Javaidentifier as other than the first character.A character may be part of a Java identifier if any of the followingconditions are true:
- it is a letter
- it is a currency symbol (such as
'$') - 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)returnstrueforthe code point
- Parameters:
codePoint- the character (Unicode code point) to be tested.- Returns:
trueif the character may be part of a Java identifier;falseotherwise.- Since:
- 1.5
- See Also:
isUnicodeIdentifierStart
public static boolean isUnicodeIdentifierStart(char ch) Determines if the specified character is permissible as thefirst character in a Unicode identifier.A character may start a Unicode identifier if and only ifone of the following conditions is true:
isLetter(ch)returnstruegetType(ch)returnsLETTER_NUMBER.- it is an
Other_ID_Startcharacter.
This method conforms toUAX31-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 toStartfor backwardcompatibility.Note: This method cannot handle supplementary characters. To supportall Unicode characters, including supplementary characters, usethe
isUnicodeIdentifierStart(int)method.- Parameters:
ch- the character to be tested.- Returns:
trueif the character may start a Unicode identifier;falseotherwise.- 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 thefirst character in a Unicode identifier.A character may start a Unicode identifier if and only ifone of the following conditions is true:
isLetter(codePoint)returnstruegetType(codePoint)returnsLETTER_NUMBER.- it is an
Other_ID_Startcharacter.
This method conforms toUAX31-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 toStartfor backwardcompatibility.- Parameters:
codePoint- the character (Unicode code point) to be tested.- Returns:
trueif the character may start a Unicode identifier;falseotherwise.- Since:
- 1.5
- External Specifications
- See Also:
isUnicodeIdentifierPart
public static boolean isUnicodeIdentifierPart(char ch) Determines if the specified character may be part of a Unicodeidentifier as other than the first character.A character may be part of a Unicode identifier if and only ifone 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
isIdentifierIgnorablereturnstruefor this character.- it is an
Other_ID_Startcharacter. - it is an
Other_ID_Continuecharacter.
This method conforms toUAX31-R1: Default Identifiers requirement of the Unicode Standard,with the following profile of UAX31:
Continue := Start + ID_Continue + ignorableMedial := emptyignorable := isIdentifierIgnorable(char) returns true for the character
ignorableis added toContinuefor backwardcompatibility.Note: This method cannot handle supplementary characters. To supportall Unicode characters, including supplementary characters, usethe
isUnicodeIdentifierPart(int)method.- Parameters:
ch- the character to be tested.- Returns:
trueif the character may be part of a Unicode identifier;falseotherwise.- 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 Unicodeidentifier as other than the first character.A character may be part of a Unicode identifier if and only ifone 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
isIdentifierIgnorablereturnstruefor this character.- it is an
Other_ID_Startcharacter. - it is an
Other_ID_Continuecharacter.
This method conforms toUAX31-R1: Default Identifiers requirement of the Unicode Standard,with the following profile of UAX31:
Continue := Start + ID_Continue + ignorableMedial := emptyignorable := isIdentifierIgnorable(int) returns true for the character
ignorableis added toContinuefor backwardcompatibility.- Parameters:
codePoint- the character (Unicode code point) to be tested.- Returns:
trueif the character may be part of a Unicode identifier;falseotherwise.- Since:
- 1.5
- External Specifications
- See Also:
isIdentifierIgnorable
public static boolean isIdentifierIgnorable(char ch) Determines if the specified character should be regarded asan ignorable character in a Java identifier or a Unicode identifier.The following Unicode characters are ignorable in a Java identifieror a Unicode identifier:
- ISO control characters that are not whitespace
'\u0000'through'\u0008''\u000E'through'\u001B''\u007F'through'\u009F'
- all characters that have the
FORMATgeneralcategory value
Note: This method cannot handle supplementary characters. To supportall Unicode characters, including supplementary characters, usethe
isIdentifierIgnorable(int)method.- Parameters:
ch- the character to be tested.- Returns:
trueif the character is an ignorable control character that may be part of a Java or Unicode identifier;falseotherwise.- 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 asan ignorable character in a Java identifier or a Unicode identifier.The following Unicode characters are ignorable in a Java identifieror a Unicode identifier:
- ISO control characters that are not whitespace
'\u0000'through'\u0008''\u000E'through'\u001B''\u007F'through'\u009F'
- all characters that have the
FORMATgeneralcategory value
- Parameters:
codePoint- the character (Unicode code point) to be tested.- Returns:
trueif the character is an ignorable control character that may be part of a Java or Unicode identifier;falseotherwise.- 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
Emojiproperty, defined inUnicode Emoji (Technical Standard #51).- Parameters:
codePoint- the character (Unicode code point) to be tested.- Returns:
trueif the character is an Emoji;falseotherwise.- Since:
- 21
- External Specifications
isEmojiPresentation
public static boolean isEmojiPresentation(int codePoint) Determines if the specified character (Unicode code point) has theEmoji Presentation property by default.A character is considered to have the Emoji Presentation property if andonly if it has the
Emoji_Presentationproperty, defined inUnicode Emoji (Technical Standard #51).- Parameters:
codePoint- the character (Unicode code point) to be tested.- Returns:
trueif the character has the Emoji Presentation property;falseotherwise.- Since:
- 21
- External Specifications
isEmojiModifier
public static boolean isEmojiModifier(int codePoint) Determines if the specified character (Unicode code point) is anEmoji Modifier.A character is considered to be an Emoji Modifier if and only if it hasthe
Emoji_Modifierproperty, defined inUnicode Emoji (Technical Standard #51).- Parameters:
codePoint- the character (Unicode code point) to be tested.- Returns:
trueif the character is an Emoji Modifier;falseotherwise.- Since:
- 21
- External Specifications
isEmojiModifierBase
public static boolean isEmojiModifierBase(int codePoint) Determines if the specified character (Unicode code point) is anEmoji Modifier Base.A character is considered to be an Emoji Modifier Base if and only if it hasthe
Emoji_Modifier_Baseproperty, defined inUnicode Emoji (Technical Standard #51).- Parameters:
codePoint- the character (Unicode code point) to be tested.- Returns:
trueif the character is an Emoji Modifier Base;falseotherwise.- Since:
- 21
- External Specifications
isEmojiComponent
public static boolean isEmojiComponent(int codePoint) Determines if the specified character (Unicode code point) is anEmoji Component.A character is considered to be an Emoji Component if and only if it hasthe
Emoji_Componentproperty, defined inUnicode Emoji (Technical Standard #51).- Parameters:
codePoint- the character (Unicode code point) to be tested.- Returns:
trueif the character is an Emoji Component;falseotherwise.- Since:
- 21
- External Specifications
isExtendedPictographic
public static boolean isExtendedPictographic(int codePoint) Determines if the specified character (Unicode code point) isan Extended Pictographic.A character is considered to be an Extended Pictographic if and only if it hasthe
Extended_Pictographicproperty, defined inUnicode Emoji (Technical Standard #51).- Parameters:
codePoint- the character (Unicode code point) to be tested.- Returns:
trueif the character is an Extended Pictographic;falseotherwise.- Since:
- 21
- External Specifications
toLowerCase
public static char toLowerCase(char ch) Converts the character argument to lowercase using casemapping information from the UnicodeData file.Note that
Character.isLowerCase(Character.toLowerCase(ch))does not always returntruefor some ranges ofcharacters, particularly those that are symbols or ideographs.In general,
String.toLowerCase()should be used to mapcharacters to lowercase.Stringcase mapping methodshave several benefits overCharactercase mapping methods.Stringcase mapping methods can perform locale-sensitivemappings, context-sensitive mappings, and 1:M character mappings, whereastheCharactercase mapping methods cannot.Note: This method cannot handle supplementary characters. To supportall Unicode characters, including supplementary characters, usethe
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 tolowercase using case mapping information from the UnicodeDatafile.Note that
Character.isLowerCase(Character.toLowerCase(codePoint))does not always returntruefor some ranges ofcharacters, particularly those that are symbols or ideographs.In general,
String.toLowerCase()should be used to mapcharacters to lowercase.Stringcase mapping methodshave several benefits overCharactercase mapping methods.Stringcase mapping methods can perform locale-sensitivemappings, context-sensitive mappings, and 1:M character mappings, whereastheCharactercase 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 mappinginformation from the UnicodeData file.Note that
Character.isUpperCase(Character.toUpperCase(ch))does not always returntruefor some ranges ofcharacters, particularly those that are symbols or ideographs.In general,
String.toUpperCase()should be used to mapcharacters to uppercase.Stringcase mapping methodshave several benefits overCharactercase mapping methods.Stringcase mapping methods can perform locale-sensitivemappings, context-sensitive mappings, and 1:M character mappings, whereastheCharactercase mapping methods cannot.Note: This method cannot handle supplementary characters. To supportall Unicode characters, including supplementary characters, usethe
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 touppercase using case mapping information from the UnicodeDatafile.Note that
Character.isUpperCase(Character.toUpperCase(codePoint))does not always returntruefor some ranges ofcharacters, particularly those that are symbols or ideographs.In general,
String.toUpperCase()should be used to mapcharacters to uppercase.Stringcase mapping methodshave several benefits overCharactercase mapping methods.Stringcase mapping methods can perform locale-sensitivemappings, context-sensitive mappings, and 1:M character mappings, whereastheCharactercase 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 mappinginformation from the UnicodeData file. If a character has noexplicit titlecase mapping and is not itself a titlecase characcording to UnicodeData, then the uppercase mapping isreturned as an equivalent titlecase mapping. If thecharargument is already a titlecasechar, the samecharvalue will bereturned.Note that
Character.isTitleCase(Character.toTitleCase(ch))does not always returntruefor some ranges ofcharacters.Note: This method cannot handle supplementary characters. To supportall Unicode characters, including supplementary characters, usethe
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 mappinginformation from the UnicodeData file. If a character has noexplicit titlecase mapping and is not itself a titlecase characcording to UnicodeData, then the uppercase mapping isreturned as an equivalent titlecase mapping. If thecharacter argument is already a titlecasecharacter, the same character value will bereturned.Note that
Character.isTitleCase(Character.toTitleCase(codePoint))does not always returntruefor some ranges ofcharacters.- 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 characterchin thespecified radix.If the radix is not in the range
MIN_RADIX≤radix≤MAX_RADIXor if thevalue ofchis not a valid digit in the specifiedradix,-1is returned. A character is a valid digitif at least one of the following is true:- The method
isDigitistrueof 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' + 10is 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' + 10is 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' + 10is 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' + 10is returned.
Note: This method cannot handle supplementary characters. To supportall Unicode characters, including supplementary characters, usethe
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 (Unicodecode point) in the specified radix.If the radix is not in the range
MIN_RADIX≤radix≤MAX_RADIXor if thecharacter is not a valid digit in the specifiedradix,-1is returned. A character is a valid digitif at least one of the following is true:- The method
isDigit(codePoint)istrueof 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' + 10is 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' + 10is 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' + 10is 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' + 10is 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 theintvalue that the specified Unicodecharacter represents. For example, the character'\u216C'(the roman numeral fifty) will returnan int with a value of 50.The letters A-Z in their uppercase (
'\u0041'through'\u005A'), lowercase('\u0061'through'\u007A'), andfull width variant ('\uFF21'through'\uFF3A'and'\uFF41'through'\uFF5A') forms have numeric values from 10through 35. This is independent of the Unicode specification,which does not assign numeric values to thesecharvalues.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 anonnegative integer (for example, a fractional value), then -2is returned.
Note: This method cannot handle supplementary characters. To supportall Unicode characters, including supplementary characters, usethe
getNumericValue(int)method.- Parameters:
ch- the character to be converted.- Returns:
- the numeric value of the character, as a nonnegative
intvalue; -2 if the character has a numeric value but the value can not be represented as a nonnegativeintvalue; -1 if the character has no numeric value. - Since:
- 1.1
- See Also:
getNumericValue
public static int getNumericValue(int codePoint) Returns theintvalue that the specifiedcharacter (Unicode code point) represents. For example, the character'\u216C'(the Roman numeral fifty) will returnanintwith a value of 50.The letters A-Z in their uppercase (
'\u0041'through'\u005A'), lowercase('\u0061'through'\u007A'), andfull width variant ('\uFF21'through'\uFF3A'and'\uFF41'through'\uFF5A') forms have numeric values from 10through 35. This is independent of the Unicode specification,which does not assign numeric values to thesecharvalues.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 anonnegative integer (for example, a fractional value), then -2is returned.
- Parameters:
codePoint- the character (Unicode code point) to be converted.- Returns:
- the numeric value of the character, as a nonnegative
intvalue; -2 if the character has a numeric value but the value can not be represented as a nonnegativeintvalue; -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 returnstruefor the following fivecharacters only:truechars Character Code Name '\t'U+0009HORIZONTAL TABULATION'\n'U+000ANEW LINE'\f'U+000CFORM FEED'\r'U+000DCARRIAGE RETURN' 'U+0020SPACE- Parameters:
ch- the character to be tested.- Returns:
trueif the character is ISO-LATIN-1 white space;falseotherwise.- 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 ifit is specified to be a space character by the Unicode Standard. Thismethod returns true if the character's general category type is any ofthe following:SPACE_SEPARATORLINE_SEPARATORPARAGRAPH_SEPARATOR
Note: This method cannot handle supplementary characters. To supportall Unicode characters, including supplementary characters, usethe
isSpaceChar(int)method.- Parameters:
ch- the character to be tested.- Returns:
trueif the character is a space character;falseotherwise.- Since:
- 1.1
- See Also:
isSpaceChar
public static boolean isSpaceChar(int codePoint) Determines if the specified character (Unicode code point) is aUnicode space character. A character is considered to be aspace character if and only if it is specified to be a spacecharacter by the Unicode Standard. This method returns true ifthe character's general category type is any of the following:- Parameters:
codePoint- the character (Unicode code point) to be tested.- Returns:
trueif the character is a space character;falseotherwise.- 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 satisfiesone 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 supportall Unicode characters, including supplementary characters, usethe
isWhitespace(int)method.- Parameters:
ch- the character to be tested.- Returns:
trueif the character is a Java whitespace character;falseotherwise.- 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) iswhite space according to Java. A character is a Javawhitespace character if and only if it satisfies one of thefollowing 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:
trueif the character is a Java whitespace character;falseotherwise.- 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 controlcharacter. A character is considered to be an ISO controlcharacter 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 supportall Unicode characters, including supplementary characters, usethe
isISOControl(int)method.- Parameters:
ch- the character to be tested.- Returns:
trueif the character is an ISO control character;falseotherwise.- Since:
- 1.1
- See Also:
isISOControl
public static boolean isISOControl(int codePoint) Determines if the referenced character (Unicode code point) is an ISO controlcharacter. A character is considered to be an ISO controlcharacter 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:
trueif the character is an ISO control character;falseotherwise.- 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 supportall Unicode characters, including supplementary characters, usethe
getType(int)method.- Parameters:
ch- the character to be tested.- Returns:
- a value of type
intrepresenting the character's general category. - Since:
- 1.1
- See Also:
COMBINING_SPACING_MARKCONNECTOR_PUNCTUATIONCONTROLCURRENCY_SYMBOLDASH_PUNCTUATIONDECIMAL_DIGIT_NUMBERENCLOSING_MARKEND_PUNCTUATIONFINAL_QUOTE_PUNCTUATIONFORMATINITIAL_QUOTE_PUNCTUATIONLETTER_NUMBERLINE_SEPARATORLOWERCASE_LETTERMATH_SYMBOLMODIFIER_LETTERMODIFIER_SYMBOLNON_SPACING_MARKOTHER_LETTEROTHER_NUMBEROTHER_PUNCTUATIONOTHER_SYMBOLPARAGRAPH_SEPARATORPRIVATE_USESPACE_SEPARATORSTART_PUNCTUATIONSURROGATETITLECASE_LETTERUNASSIGNEDUPPERCASE_LETTER
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
intrepresenting the character's general category. - Since:
- 1.5
- See Also:
COMBINING_SPACING_MARKCONNECTOR_PUNCTUATIONCONTROLCURRENCY_SYMBOLDASH_PUNCTUATIONDECIMAL_DIGIT_NUMBERENCLOSING_MARKEND_PUNCTUATIONFINAL_QUOTE_PUNCTUATIONFORMATINITIAL_QUOTE_PUNCTUATIONLETTER_NUMBERLINE_SEPARATORLOWERCASE_LETTERMATH_SYMBOLMODIFIER_LETTERMODIFIER_SYMBOLNON_SPACING_MARKOTHER_LETTEROTHER_NUMBEROTHER_PUNCTUATIONOTHER_SYMBOLPARAGRAPH_SEPARATORPRIVATE_USESPACE_SEPARATORSTART_PUNCTUATIONSURROGATETITLECASE_LETTERUNASSIGNEDUPPERCASE_LETTER
forDigit
public static char forDigit(int digit, int radix) Determines the character representation for a specific digit inthe specified radix. If the value ofradixis not avalid radix, or the value ofdigitis not a validdigit in the specified radix, the null character('\u0000') is returned.The
radixargument is valid if it is greater than orequal toMIN_RADIXand less than or equal toMAX_RADIX. Thedigitargument is valid if0 <= digit < radix.If the digit is less than 10, then
'0' + digitis returned. Otherwise, the value'a' + digit - 10is returned.- Parameters:
digit- the number to convert to a character.radix- the radix.- Returns:
- the
charrepresentation of the specified digit in the specified radix. - See Also:
getDirectionality
public static byte getDirectionality(char ch) Returns the Unicode directionality property for the givencharacter. Character directionality is used to calculate thevisual ordering of text. The directionality value of undefinedcharvalues isDIRECTIONALITY_UNDEFINED.Note: This method cannot handle supplementary characters. To supportall Unicode characters, including supplementary characters, usethe
getDirectionality(int)method.- Parameters:
ch-charfor which the directionality property is requested.- Returns:
- the directionality property of the
charvalue. - Since:
- 1.4
- See Also:
DIRECTIONALITY_UNDEFINEDDIRECTIONALITY_LEFT_TO_RIGHTDIRECTIONALITY_RIGHT_TO_LEFTDIRECTIONALITY_RIGHT_TO_LEFT_ARABICDIRECTIONALITY_EUROPEAN_NUMBERDIRECTIONALITY_EUROPEAN_NUMBER_SEPARATORDIRECTIONALITY_EUROPEAN_NUMBER_TERMINATORDIRECTIONALITY_ARABIC_NUMBERDIRECTIONALITY_COMMON_NUMBER_SEPARATORDIRECTIONALITY_NONSPACING_MARKDIRECTIONALITY_BOUNDARY_NEUTRALDIRECTIONALITY_PARAGRAPH_SEPARATORDIRECTIONALITY_SEGMENT_SEPARATORDIRECTIONALITY_WHITESPACEDIRECTIONALITY_OTHER_NEUTRALSDIRECTIONALITY_LEFT_TO_RIGHT_EMBEDDINGDIRECTIONALITY_LEFT_TO_RIGHT_OVERRIDEDIRECTIONALITY_RIGHT_TO_LEFT_EMBEDDINGDIRECTIONALITY_RIGHT_TO_LEFT_OVERRIDEDIRECTIONALITY_POP_DIRECTIONAL_FORMATDIRECTIONALITY_LEFT_TO_RIGHT_ISOLATEDIRECTIONALITY_RIGHT_TO_LEFT_ISOLATEDIRECTIONALITY_FIRST_STRONG_ISOLATEDIRECTIONALITY_POP_DIRECTIONAL_ISOLATE
getDirectionality
public static byte getDirectionality(int codePoint) Returns the Unicode directionality property for the givencharacter (Unicode code point). Character directionality isused to calculate the visual ordering of text. Thedirectionality 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:
DIRECTIONALITY_UNDEFINEDDIRECTIONALITY_LEFT_TO_RIGHTDIRECTIONALITY_RIGHT_TO_LEFTDIRECTIONALITY_RIGHT_TO_LEFT_ARABICDIRECTIONALITY_EUROPEAN_NUMBERDIRECTIONALITY_EUROPEAN_NUMBER_SEPARATORDIRECTIONALITY_EUROPEAN_NUMBER_TERMINATORDIRECTIONALITY_ARABIC_NUMBERDIRECTIONALITY_COMMON_NUMBER_SEPARATORDIRECTIONALITY_NONSPACING_MARKDIRECTIONALITY_BOUNDARY_NEUTRALDIRECTIONALITY_PARAGRAPH_SEPARATORDIRECTIONALITY_SEGMENT_SEPARATORDIRECTIONALITY_WHITESPACEDIRECTIONALITY_OTHER_NEUTRALSDIRECTIONALITY_LEFT_TO_RIGHT_EMBEDDINGDIRECTIONALITY_LEFT_TO_RIGHT_OVERRIDEDIRECTIONALITY_RIGHT_TO_LEFT_EMBEDDINGDIRECTIONALITY_RIGHT_TO_LEFT_OVERRIDEDIRECTIONALITY_POP_DIRECTIONAL_FORMATDIRECTIONALITY_LEFT_TO_RIGHT_ISOLATEDIRECTIONALITY_RIGHT_TO_LEFT_ISOLATEDIRECTIONALITY_FIRST_STRONG_ISOLATEDIRECTIONALITY_POP_DIRECTIONAL_ISOLATE
isMirrored
public static boolean isMirrored(char ch) Determines whether the character is mirrored according to theUnicode specification. Mirrored characters should have theirglyphs horizontally mirrored when displayed in text that isright-to-left. For example,'\u0028'LEFTPARENTHESIS is semantically defined to be anopeningparenthesis. This will appear as a "(" in text that isleft-to-right but as a ")" in text that is right-to-left.Note: This method cannot handle supplementary characters. To supportall Unicode characters, including supplementary characters, usethe
isMirrored(int)method.- Parameters:
ch-charfor which the mirrored property is requested- Returns:
trueif the char is mirrored,falseif thecharis 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. Mirroredcharacters should have their glyphs horizontally mirrored whendisplayed in text that is right-to-left. For example,'\u0028'LEFT PARENTHESIS is semanticallydefined to be anopening parenthesis. This will appearas a "(" in text that is left-to-right but as a ")" in textthat is right-to-left.- Parameters:
codePoint- the character (Unicode code point) to be tested.- Returns:
trueif the character is mirrored,falseif the character is not mirrored or is not defined.- Since:
- 1.5
compareTo
Compares twoCharacterobjects numerically.- Specified by:
compareToin interfaceComparable<Character>- Parameters:
anotherCharacter- theCharacterto be compared.- Returns:
- the value
0if the argumentCharacteris equal to thisCharacter; a value less than0if thisCharacteris numerically less than theCharacterargument; and a value greater than0if thisCharacteris numerically greater than theCharacterargument (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 twocharvalues numerically.The value returned is identical to what would be returned by:Character.valueOf(x).compareTo(Character.valueOf(y))
- Parameters:
x- the firstcharto comparey- the secondcharto compare- Returns:
- the value
0ifx == y; a value less than0ifx < y; and a value greater than0ifx > y - Since:
- 1.7
reverseBytes
public static char reverseBytes(char ch) Returns the value obtained by reversing the order of the bytes in thespecifiedcharvalue.- Parameters:
ch- Thecharof which to reverse the byte order.- Returns:
- the value obtained by reversing (or, equivalently, swapping) the bytes in the specified
charvalue. - 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 bytheUnicodeData file (part of the Unicode CharacterDatabase maintained by the Unicode Consortium), the returnedname is the same as the result of the expression:
For theCharacter.UnicodeBlock.of(codePoint).toString().replace('_', ' ') + " " + Integer.toHexString(codePoint).toUpperCase(Locale.ROOT);codePoints in theUnicodeData file, the namereturned by this method follows the naming scheme in the"Unicode Name Property" section of the Unicode Standard. For othercode points, such as Hangul/Ideographs, The name generation rule abovediffers 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 specifiedcodePointis not a valid Unicode code point.- Since:
- 1.7
codePointOf
Returns the code point value of the Unicode character specified bythe given character name.If a character is not assigned a name by theUnicodeDatafile (part of the Unicode Character Database maintained by the UnicodeConsortium), its name is defined as the result of the expression:
Character.UnicodeBlock.of(codePoint).toString().replace('_', ' ') + " " + Integer.toHexString(codePoint).toUpperCase(Locale.ROOT);The
namematching is case insensitive, with any leading andtrailing whitespace character removed.For the code points in theUnicodeData file, this methodrecognizes the name which conforms to the name defined in the"Unicode Name Property" section in the Unicode Standard. For othercode 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 specifiednameis not a valid character name.NullPointerException- ifnameisnull- Since:
- 9