Class Character

java.lang.Object
java.lang.Character
All Implemented Interfaces:
Serializable,Comparable<Character>,Constable

public final classCharacterextendsObjectimplementsSerializable,Comparable<Character>,Constable
TheCharacter class is thewrapper class for values of the primitive typechar. An object of typeCharacter contains a single field whose type ischar.

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

Unicode Conformance

The fields and methods of classCharacter are defined in terms of 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 every assigned Unicode code point or character range. The file is available from 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 Unicode Standard over time. Upgrades to newer versions of the Unicode Standard occurred in the following Java releases, each indicating the new version:

Shows Java releases and supported Unicode versions
Java releaseUnicode version
Java SE 24Unicode 16.0
Java SE 22Unicode 15.1
Java SE 20Unicode 15.0
Java SE 19Unicode 14.0
Java SE 15Unicode 13.0
Java SE 13Unicode 12.1
Java SE 12Unicode 11.0
Java SE 11Unicode 10.0
Java SE 9Unicode 8.0
Java SE 8Unicode 6.2
Java SE 7Unicode 6.0
Java SE 5.0Unicode 4.0
Java SE 1.4Unicode 3.0
JDK 1.1Unicode 2.0
JDK 1.0.2Unicode 1.1.5
Variations from these base Unicode versions, such as recognized appendixes, are documented elsewhere.

Unicode Character Representations

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

The set of characters from U+0000 to U+FFFF is sometimes referred to as theBasic Multilingual Plane (BMP).Characters whose code points are greater than U+FFFF are calledsupplementary characters. The Java platform uses the UTF-16 representation inchar arrays and in theString andStringBuffer classes. In this representation, supplementary characters are represented as a pair ofchar values, the first from thehigh-surrogates range, (\uD800-\uDBFF), the second from thelow-surrogates range (\uDC00-\uDFFF).

Achar value, therefore, represents Basic Multilingual Plane (BMP) code points, including the surrogate code 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 code points and the upper (most significant) 11 bits must be zero. Unless otherwise specified, the behavior with respect to supplementary characters and surrogatechar values is as follows:

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

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

This is avalue-based class; programmers should treat instances that areequal as interchangeable and should not use instances for synchronization, or unpredictable behavior may occur. For example, in a future release, synchronization may fail.

Since:
1.0
External Specifications
See Also:
  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    static class 
    Instances of this class represent particular subsets of the Unicode character set.
    static final class 
    A family of character subsets representing the character blocks in the Unicode specification.
    static enum 
    A family of character subsets representing the character scripts defined in theUnicode Standard Annex #24: Script Names.
  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final int
    The number of bytes used to represent achar value in unsigned binary form.
    static final byte
    General category "Mc" in the Unicode specification.
    static final byte
    General category "Pc" in the Unicode specification.
    static final byte
    General category "Cc" in the Unicode specification.
    static final byte
    General category "Sc" in the Unicode specification.
    static final byte
    General category "Pd" in the Unicode specification.
    static final byte
    General category "Nd" in the Unicode specification.
    static final byte
    Weak bidirectional character type "AN" in the Unicode specification.
    static final byte
    Weak bidirectional character type "BN" in the Unicode specification.
    static final byte
    Weak bidirectional character type "CS" in the Unicode specification.
    static final byte
    Weak bidirectional character type "EN" in the Unicode specification.
    static final byte
    Weak bidirectional character type "ES" in the Unicode specification.
    static final byte
    Weak bidirectional character type "ET" in the Unicode specification.
    static final byte
    Weak bidirectional character type "FSI" in the Unicode specification.
    static final byte
    Strong bidirectional character type "L" in the Unicode specification.
    static final byte
    Strong bidirectional character type "LRE" in the Unicode specification.
    static final byte
    Weak bidirectional character type "LRI" in the Unicode specification.
    static final byte
    Strong bidirectional character type "LRO" in the Unicode specification.
    static final byte
    Weak bidirectional character type "NSM" in the Unicode specification.
    static final byte
    Neutral bidirectional character type "ON" in the Unicode specification.
    static final byte
    Neutral bidirectional character type "B" in the Unicode specification.
    static final byte
    Weak bidirectional character type "PDF" in the Unicode specification.
    static final byte
    Weak bidirectional character type "PDI" in the Unicode specification.
    static final byte
    Strong bidirectional character type "R" in the Unicode specification.
    static final byte
    Strong bidirectional character type "AL" in the Unicode specification.
    static final byte
    Strong bidirectional character type "RLE" in the Unicode specification.
    static final byte
    Weak bidirectional character type "RLI" in the Unicode specification.
    static final byte
    Strong bidirectional character type "RLO" in the Unicode specification.
    static final byte
    Neutral bidirectional character type "S" in the Unicode specification.
    static final byte
    Undefined bidirectional character type.
    static final byte
    Neutral bidirectional character type "WS" in the Unicode specification.
    static final byte
    General category "Me" in the Unicode specification.
    static final byte
    General category "Pe" in the Unicode specification.
    static final byte
    General category "Pf" in the Unicode specification.
    static final byte
    General category "Cf" in the Unicode specification.
    static final byte
    General category "Pi" in the Unicode specification.
    static final byte
    General category "Nl" in the Unicode specification.
    static final byte
    General category "Zl" in the Unicode specification.
    static final byte
    General category "Ll" in the Unicode specification.
    static final byte
    General category "Sm" in the Unicode specification.
    static final int
    The maximum value of a Unicode code point, constantU+10FFFF.
    static final char
    The maximum value of a Unicode high-surrogate code unit in the UTF-16 encoding, constant'\uDBFF'.
    static final char
    The maximum value of a Unicode low-surrogate code unit in the UTF-16 encoding, constant'\uDFFF'.
    static final int
    The maximum radix available for conversion to and from strings.
    static final char
    The maximum value of a Unicode surrogate code unit in the UTF-16 encoding, constant'\uDFFF'.
    static final char
    The constant value of this field is the largest value of typechar,'\uFFFF'.
    static final int
    The minimum value of a Unicode code point, constantU+0000.
    static final char
    The minimum value of a Unicode high-surrogate code unit in the UTF-16 encoding, constant'\uD800'.
    static final char
    The minimum value of a Unicode low-surrogate code unit in the UTF-16 encoding, constant'\uDC00'.
    static final int
    The minimum radix available for conversion to and from strings.
    static final int
    The minimum value of a Unicode supplementary code point, constantU+10000.
    static final char
    The minimum value of a Unicode surrogate code unit in the UTF-16 encoding, constant'\uD800'.
    static final char
    The constant value of this field is the smallest value of typechar,'\u0000'.
    static final byte
    General category "Lm" in the Unicode specification.
    static final byte
    General category "Sk" in the Unicode specification.
    static final byte
    General category "Mn" in the Unicode specification.
    static final byte
    General category "Lo" in the Unicode specification.
    static final byte
    General category "No" in the Unicode specification.
    static final byte
    General category "Po" in the Unicode specification.
    static final byte
    General category "So" in the Unicode specification.
    static final byte
    General category "Zp" in the Unicode specification.
    static final byte
    General category "Co" in the Unicode specification.
    static final int
    The number of bits used to represent achar value in unsigned binary form, constant16.
    static final byte
    General category "Zs" in the Unicode specification.
    static final byte
    General category "Ps" in the Unicode specification.
    static final byte
    General category "Cs" in the Unicode specification.
    static final byte
    General category "Lt" in the Unicode specification.
    static finalClass<Character>
    TheClass instance representing the primitive typechar.
    static final byte
    General category "Cn" in the Unicode specification.
    static final byte
    General category "Lu" in the Unicode specification.
  • Constructor Summary

    Constructors
    Constructor
    Description
    Character(char value)
    Deprecated, for removal: This API element is subject to removal in a future version.
    It is rarely appropriate to use this constructor.
  • Method Summary

    Modifier and Type
    Method
    Description
    static int
    charCount(int codePoint)
    Determines the number ofchar values needed to represent the specified character (Unicode code point).
    char
    Returns the value of thisCharacter object.
    static int
    codePointAt(char[] a, int index)
    Returns the code point at the given index of thechar array.
    static int
    codePointAt(char[] a, int index, int limit)
    Returns the code point at the given index of thechar array, where only array elements withindex less thanlimit can be used.
    static int
    codePointAt(CharSequence seq, int index)
    Returns the code point at the given index of theCharSequence.
    static int
    codePointBefore(char[] a, int index)
    Returns the code point preceding the given index of thechar array.
    static int
    codePointBefore(char[] a, int index, int start)
    Returns the code point preceding the given index of thechar array, where only array elements withindex greater than or equal tostart can be used.
    static int
    codePointBefore(CharSequence seq, int index)
    Returns the code point preceding the given index of theCharSequence.
    static int
    codePointCount(char[] a, int offset, int count)
    Returns the number of Unicode code points in a subarray of thechar array argument.
    static int
    codePointCount(CharSequence seq, int beginIndex, int endIndex)
    Returns the number of Unicode code points in the text range of the specified char sequence.
    static int
    Returns the code point value of the Unicode character specified by the given character name.
    static int
    compare(char x, char y)
    Compares twochar values numerically.
    int
    compareTo(Character anotherCharacter)
    Compares twoCharacter objects numerically.
    Returns anOptional containing the nominal descriptor for this instance.
    static int
    digit(char ch, int radix)
    Returns the numeric value of the characterch in the specified radix.
    static int
    digit(int codePoint, int radix)
    Returns the numeric value of the specified character (Unicode code point) in the specified radix.
    boolean
    Compares this object against the specified object.
    static char
    forDigit(int digit, int radix)
    Determines the character representation for a specific digit in the specified radix.
    static byte
    Returns the Unicode directionality property for the given character.
    static byte
    getDirectionality(int codePoint)
    Returns the Unicode directionality property for the given character (Unicode code point).
    staticString
    getName(int codePoint)
    Returns the name of the specified charactercodePoint, or null if the code point isunassigned.
    static int
    getNumericValue(char ch)
    Returns theint value that the specified Unicode character represents.
    static int
    getNumericValue(int codePoint)
    Returns theint value that the specified character (Unicode code point) represents.
    static int
    getType(char ch)
    Returns a value indicating a character's general category.
    static int
    getType(int codePoint)
    Returns a value indicating a character's general category.
    int
    Returns a hash code for thisCharacter; equal to the result of invokingcharValue().
    static int
    hashCode(char value)
    Returns a hash code for achar value; compatible withCharacter.hashCode().
    static char
    highSurrogate(int codePoint)
    Returns the leading surrogate (a high surrogate code unit) of the surrogate pair representing the specified supplementary character (Unicode code point) in the UTF-16 encoding.
    static boolean
    isAlphabetic(int codePoint)
    Determines if the specified character (Unicode code point) is alphabetic.
    static boolean
    isBmpCodePoint(int codePoint)
    Determines whether the specified character (Unicode code point) is in theBasic Multilingual Plane (BMP).
    static boolean
    isDefined(char ch)
    Determines if a character is defined in Unicode.
    static boolean
    isDefined(int codePoint)
    Determines if a character (Unicode code point) is defined in Unicode.
    static boolean
    isDigit(char ch)
    Determines if the specified character is a digit.
    static boolean
    isDigit(int codePoint)
    Determines if the specified character (Unicode code point) is a digit.
    static boolean
    isEmoji(int codePoint)
    Determines if the specified character (Unicode code point) is an Emoji.
    static boolean
    isEmojiComponent(int codePoint)
    Determines if the specified character (Unicode code point) is an Emoji Component.
    static boolean
    isEmojiModifier(int codePoint)
    Determines if the specified character (Unicode code point) is an Emoji Modifier.
    static boolean
    isEmojiModifierBase(int codePoint)
    Determines if the specified character (Unicode code point) is an Emoji Modifier Base.
    static boolean
    isEmojiPresentation(int codePoint)
    Determines if the specified character (Unicode code point) has the Emoji Presentation property by default.
    static boolean
    isExtendedPictographic(int codePoint)
    Determines if the specified character (Unicode code point) is an Extended Pictographic.
    static boolean
    isHighSurrogate(char ch)
    Determines if the givenchar value is a Unicode high-surrogate code unit (also known asleading-surrogate code unit).
    static boolean
    Determines if the specified character should be regarded as an ignorable character in a Java identifier or a Unicode identifier.
    static boolean
    isIdentifierIgnorable(int codePoint)
    Determines if the specified character (Unicode code point) should be regarded as an ignorable character in a Java identifier or a Unicode identifier.
    static boolean
    isIdeographic(int codePoint)
    Determines if the specified character (Unicode code point) is a CJKV (Chinese, Japanese, Korean and Vietnamese) ideograph, as defined by the Unicode Standard.
    static boolean
    isISOControl(char ch)
    Determines if the specified character is an ISO control character.
    static boolean
    isISOControl(int codePoint)
    Determines if the referenced character (Unicode code point) is an ISO control character.
    static boolean
    Determines if the specified character may be part of a Java identifier as other than the first character.
    static boolean
    isJavaIdentifierPart(int codePoint)
    Determines if the character (Unicode code point) may be part of a Java identifier as other than the first character.
    static boolean
    Determines if the specified character is permissible as the first character in a Java identifier.
    static boolean
    isJavaIdentifierStart(int codePoint)
    Determines if the character (Unicode code point) is permissible as the first character in a Java identifier.
    static boolean
    isJavaLetter(char ch)
    Deprecated.
    Replaced by isJavaIdentifierStart(char).
    static boolean
    Deprecated.
    Replaced by isJavaIdentifierPart(char).
    static boolean
    isLetter(char ch)
    Determines if the specified character is a letter.
    static boolean
    isLetter(int codePoint)
    Determines if the specified character (Unicode code point) is a letter.
    static boolean
    isLetterOrDigit(char ch)
    Determines if the specified character is a letter or digit.
    static boolean
    isLetterOrDigit(int codePoint)
    Determines if the specified character (Unicode code point) is a letter or digit.
    static boolean
    isLowerCase(char ch)
    Determines if the specified character is a lowercase character.
    static boolean
    isLowerCase(int codePoint)
    Determines if the specified character (Unicode code point) is a lowercase character.
    static boolean
    isLowSurrogate(char ch)
    Determines if the givenchar value is a Unicode low-surrogate code unit (also known astrailing-surrogate code unit).
    static boolean
    isMirrored(char ch)
    Determines whether the character is mirrored according to the Unicode specification.
    static boolean
    isMirrored(int codePoint)
    Determines whether the specified character (Unicode code point) is mirrored according to the Unicode specification.
    static boolean
    isSpace(char ch)
    Deprecated.
    Replaced by isWhitespace(char).
    static boolean
    isSpaceChar(char ch)
    Determines if the specified character is a Unicode space character.
    static boolean
    isSpaceChar(int codePoint)
    Determines if the specified character (Unicode code point) is a Unicode space character.
    static boolean
    isSupplementaryCodePoint(int codePoint)
    Determines whether the specified character (Unicode code point) is in thesupplementary character range.
    static boolean
    isSurrogate(char ch)
    Determines if the givenchar value is a Unicodesurrogate code unit.
    static boolean
    isSurrogatePair(char high, char low)
    Determines whether the specified pair ofchar values is a valid Unicode surrogate pair.
    static boolean
    isTitleCase(char ch)
    Determines if the specified character is a titlecase character.
    static boolean
    isTitleCase(int codePoint)
    Determines if the specified character (Unicode code point) is a titlecase character.
    static boolean
    Determines if the specified character may be part of a Unicode identifier as other than the first character.
    static boolean
    isUnicodeIdentifierPart(int codePoint)
    Determines if the specified character (Unicode code point) may be part of a Unicode identifier as other than the first character.
    static boolean
    Determines if the specified character is permissible as the first character in a Unicode identifier.
    static boolean
    isUnicodeIdentifierStart(int codePoint)
    Determines if the specified character (Unicode code point) is permissible as the first character in a Unicode identifier.
    static boolean
    isUpperCase(char ch)
    Determines if the specified character is an uppercase character.
    static boolean
    isUpperCase(int codePoint)
    Determines if the specified character (Unicode code point) is an uppercase character.
    static boolean
    isValidCodePoint(int codePoint)
    Determines whether the specified code point is a valid Unicode code point value.
    static boolean
    isWhitespace(char ch)
    Determines if the specified character is white space according to Java.
    static boolean
    isWhitespace(int codePoint)
    Determines if the specified character (Unicode code point) is white space according to Java.
    static char
    lowSurrogate(int codePoint)
    Returns the trailing surrogate (a low surrogate code unit) of the surrogate pair representing the specified supplementary character (Unicode code point) in the UTF-16 encoding.
    static int
    offsetByCodePoints(char[] a, int start, int count, int index, int codePointOffset)
    Returns the index within the givenchar subarray that is offset from the givenindex bycodePointOffset code points.
    static int
    offsetByCodePoints(CharSequence seq, int index, int codePointOffset)
    Returns the index within the given char sequence that is offset from the givenindex bycodePointOffset code points.
    static char
    reverseBytes(char ch)
    Returns the value obtained by reversing the order of the bytes in the specifiedchar value.
    static char[]
    toChars(int codePoint)
    Converts the specified character (Unicode code point) to its UTF-16 representation stored in achar array.
    static int
    toChars(int codePoint, char[] dst, int dstIndex)
    Converts the specified character (Unicode code point) to its UTF-16 representation.
    static int
    toCodePoint(char high, char low)
    Converts the specified surrogate pair to its supplementary code point value.
    static char
    toLowerCase(char ch)
    Converts the character argument to lowercase using case mapping information from the UnicodeData file.
    static int
    toLowerCase(int codePoint)
    Converts the character (Unicode code point) argument to lowercase using case mapping information from the UnicodeData file.
    Returns aString object representing thisCharacter's value.
    staticString
    toString(char c)
    Returns aString object representing the specifiedchar.
    staticString
    toString(int codePoint)
    Returns aString object representing the specified character (Unicode code point).
    static char
    toTitleCase(char ch)
    Converts the character argument to titlecase using case mapping information from the UnicodeData file.
    static int
    toTitleCase(int codePoint)
    Converts the character (Unicode code point) argument to titlecase using case mapping information from the UnicodeData file.
    static char
    toUpperCase(char ch)
    Converts the character argument to uppercase using case mapping information from the UnicodeData file.
    static int
    toUpperCase(int codePoint)
    Converts the character (Unicode code point) argument to uppercase using case mapping information from the UnicodeData file.
    staticCharacter
    valueOf(char c)
    Returns aCharacter instance representing the specifiedchar value.

    Methods declared in class java.lang.Object

    clone,finalize,getClass,notify,notifyAll,wait,wait,wait
  • Field Details

    • MIN_RADIX

      public static final int MIN_RADIX
      The minimum radix available for conversion to and from strings. The constant value of this field is the smallest value permitted for the radix argument in radix-conversion methods such as thedigit method, theforDigit method, and thetoString method of classInteger.
      See Also:
    • MAX_RADIX

      public static final int MAX_RADIX
      The maximum radix available for conversion to and from strings. The constant value of this field is the largest value permitted for the radix argument in radix-conversion methods such as thedigit method, theforDigit method, and thetoString method of classInteger.
      See Also:
    • MIN_VALUE

      public static final char MIN_VALUE
      The 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_VALUE
      The constant value of this field is the largest value of typechar,'\uFFFF'.
      Since:
      1.0.2
      See Also:
    • TYPE

      public static final Class<Character> TYPE
      TheClass instance representing the primitive typechar.
      Since:
      1.1
    • UNASSIGNED

      public static final byte UNASSIGNED
      General category "Cn" in the Unicode specification.
      Since:
      1.1
      See Also:
    • UPPERCASE_LETTER

      public static final byte UPPERCASE_LETTER
      General category "Lu" in the Unicode specification.
      Since:
      1.1
      See Also:
    • LOWERCASE_LETTER

      public static final byte LOWERCASE_LETTER
      General category "Ll" in the Unicode specification.
      Since:
      1.1
      See Also:
    • TITLECASE_LETTER

      public static final byte TITLECASE_LETTER
      General category "Lt" in the Unicode specification.
      Since:
      1.1
      See Also:
    • MODIFIER_LETTER

      public static final byte MODIFIER_LETTER
      General category "Lm" in the Unicode specification.
      Since:
      1.1
      See Also:
    • OTHER_LETTER

      public static final byte OTHER_LETTER
      General category "Lo" in the Unicode specification.
      Since:
      1.1
      See Also:
    • NON_SPACING_MARK

      public static final byte NON_SPACING_MARK
      General category "Mn" in the Unicode specification.
      Since:
      1.1
      See Also:
    • ENCLOSING_MARK

      public static final byte ENCLOSING_MARK
      General category "Me" in the Unicode specification.
      Since:
      1.1
      See Also:
    • COMBINING_SPACING_MARK

      public static final byte COMBINING_SPACING_MARK
      General category "Mc" in the Unicode specification.
      Since:
      1.1
      See Also:
    • DECIMAL_DIGIT_NUMBER

      public static final byte DECIMAL_DIGIT_NUMBER
      General category "Nd" in the Unicode specification.
      Since:
      1.1
      See Also:
    • LETTER_NUMBER

      public static final byte LETTER_NUMBER
      General category "Nl" in the Unicode specification.
      Since:
      1.1
      See Also:
    • OTHER_NUMBER

      public static final byte OTHER_NUMBER
      General category "No" in the Unicode specification.
      Since:
      1.1
      See Also:
    • SPACE_SEPARATOR

      public static final byte SPACE_SEPARATOR
      General category "Zs" in the Unicode specification.
      Since:
      1.1
      See Also:
    • LINE_SEPARATOR

      public static final byte LINE_SEPARATOR
      General category "Zl" in the Unicode specification.
      Since:
      1.1
      See Also:
    • PARAGRAPH_SEPARATOR

      public static final byte PARAGRAPH_SEPARATOR
      General category "Zp" in the Unicode specification.
      Since:
      1.1
      See Also:
    • CONTROL

      public static final byte CONTROL
      General category "Cc" in the Unicode specification.
      Since:
      1.1
      See Also:
    • FORMAT

      public static final byte FORMAT
      General category "Cf" in the Unicode specification.
      Since:
      1.1
      See Also:
    • PRIVATE_USE

      public static final byte PRIVATE_USE
      General category "Co" in the Unicode specification.
      Since:
      1.1
      See Also:
    • SURROGATE

      public static final byte SURROGATE
      General category "Cs" in the Unicode specification.
      Since:
      1.1
      See Also:
    • DASH_PUNCTUATION

      public static final byte DASH_PUNCTUATION
      General category "Pd" in the Unicode specification.
      Since:
      1.1
      See Also:
    • START_PUNCTUATION

      public static final byte START_PUNCTUATION
      General category "Ps" in the Unicode specification.
      Since:
      1.1
      See Also:
    • END_PUNCTUATION

      public static final byte END_PUNCTUATION
      General category "Pe" in the Unicode specification.
      Since:
      1.1
      See Also:
    • CONNECTOR_PUNCTUATION

      public static final byte CONNECTOR_PUNCTUATION
      General category "Pc" in the Unicode specification.
      Since:
      1.1
      See Also:
    • OTHER_PUNCTUATION

      public static final byte OTHER_PUNCTUATION
      General category "Po" in the Unicode specification.
      Since:
      1.1
      See Also:
    • MATH_SYMBOL

      public static final byte MATH_SYMBOL
      General category "Sm" in the Unicode specification.
      Since:
      1.1
      See Also:
    • CURRENCY_SYMBOL

      public static final byte CURRENCY_SYMBOL
      General category "Sc" in the Unicode specification.
      Since:
      1.1
      See Also:
    • MODIFIER_SYMBOL

      public static final byte MODIFIER_SYMBOL
      General category "Sk" in the Unicode specification.
      Since:
      1.1
      See Also:
    • OTHER_SYMBOL

      public static final byte OTHER_SYMBOL
      General category "So" in the Unicode specification.
      Since:
      1.1
      See Also:
    • INITIAL_QUOTE_PUNCTUATION

      public static final byte INITIAL_QUOTE_PUNCTUATION
      General category "Pi" in the Unicode specification.
      Since:
      1.4
      See Also:
    • FINAL_QUOTE_PUNCTUATION

      public static final byte FINAL_QUOTE_PUNCTUATION
      General category "Pf" in the Unicode specification.
      Since:
      1.4
      See Also:
    • DIRECTIONALITY_UNDEFINED

      public static final byte DIRECTIONALITY_UNDEFINED
      Undefined bidirectional character type. Undefinedchar values have undefined directionality in the Unicode specification.
      Since:
      1.4
      See Also:
    • DIRECTIONALITY_LEFT_TO_RIGHT

      public static final byte DIRECTIONALITY_LEFT_TO_RIGHT
      Strong bidirectional character type "L" in the Unicode specification.
      Since:
      1.4
      See Also:
    • DIRECTIONALITY_RIGHT_TO_LEFT

      public static final byte DIRECTIONALITY_RIGHT_TO_LEFT
      Strong 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_ARABIC
      Strong bidirectional character type "AL" in the Unicode specification.
      Since:
      1.4
      See Also:
    • DIRECTIONALITY_EUROPEAN_NUMBER

      public static final byte DIRECTIONALITY_EUROPEAN_NUMBER
      Weak bidirectional character type "EN" in the Unicode specification.
      Since:
      1.4
      See Also:
    • DIRECTIONALITY_EUROPEAN_NUMBER_SEPARATOR

      public static final byte DIRECTIONALITY_EUROPEAN_NUMBER_SEPARATOR
      Weak bidirectional character type "ES" in the Unicode specification.
      Since:
      1.4
      See Also:
    • DIRECTIONALITY_EUROPEAN_NUMBER_TERMINATOR

      public static final byte DIRECTIONALITY_EUROPEAN_NUMBER_TERMINATOR
      Weak bidirectional character type "ET" in the Unicode specification.
      Since:
      1.4
      See Also:
    • DIRECTIONALITY_ARABIC_NUMBER

      public static final byte DIRECTIONALITY_ARABIC_NUMBER
      Weak bidirectional character type "AN" in the Unicode specification.
      Since:
      1.4
      See Also:
    • DIRECTIONALITY_COMMON_NUMBER_SEPARATOR

      public static final byte DIRECTIONALITY_COMMON_NUMBER_SEPARATOR
      Weak bidirectional character type "CS" in the Unicode specification.
      Since:
      1.4
      See Also:
    • DIRECTIONALITY_NONSPACING_MARK

      public static final byte DIRECTIONALITY_NONSPACING_MARK
      Weak bidirectional character type "NSM" in the Unicode specification.
      Since:
      1.4
      See Also:
    • DIRECTIONALITY_BOUNDARY_NEUTRAL

      public static final byte DIRECTIONALITY_BOUNDARY_NEUTRAL
      Weak bidirectional character type "BN" in the Unicode specification.
      Since:
      1.4
      See Also:
    • DIRECTIONALITY_PARAGRAPH_SEPARATOR

      public static final byte DIRECTIONALITY_PARAGRAPH_SEPARATOR
      Neutral bidirectional character type "B" in the Unicode specification.
      Since:
      1.4
      See Also:
    • DIRECTIONALITY_SEGMENT_SEPARATOR

      public static final byte DIRECTIONALITY_SEGMENT_SEPARATOR
      Neutral bidirectional character type "S" in the Unicode specification.
      Since:
      1.4
      See Also:
    • DIRECTIONALITY_WHITESPACE

      public static final byte DIRECTIONALITY_WHITESPACE
      Neutral bidirectional character type "WS" in the Unicode specification.
      Since:
      1.4
      See Also:
    • DIRECTIONALITY_OTHER_NEUTRALS

      public static final byte DIRECTIONALITY_OTHER_NEUTRALS
      Neutral 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_EMBEDDING
      Strong 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_OVERRIDE
      Strong 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_EMBEDDING
      Strong 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_OVERRIDE
      Strong bidirectional character type "RLO" in the Unicode specification.
      Since:
      1.4
      See Also:
    • DIRECTIONALITY_POP_DIRECTIONAL_FORMAT

      public static final byte DIRECTIONALITY_POP_DIRECTIONAL_FORMAT
      Weak 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_ISOLATE
      Weak 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_ISOLATE
      Weak bidirectional character type "RLI" in the Unicode specification.
      Since:
      9
      See Also:
    • DIRECTIONALITY_FIRST_STRONG_ISOLATE

      public static final byte DIRECTIONALITY_FIRST_STRONG_ISOLATE
      Weak bidirectional character type "FSI" in the Unicode specification.
      Since:
      9
      See Also:
    • DIRECTIONALITY_POP_DIRECTIONAL_ISOLATE

      public static final byte DIRECTIONALITY_POP_DIRECTIONAL_ISOLATE
      Weak bidirectional character type "PDI" in the Unicode specification.
      Since:
      9
      See Also:
    • MIN_HIGH_SURROGATE

      public static final char MIN_HIGH_SURROGATE
      The minimum value of a Unicode high-surrogate code unit in the UTF-16 encoding, constant'\uD800'. A high-surrogate is also known as aleading-surrogate.
      Since:
      1.5
      See Also:
    • MAX_HIGH_SURROGATE

      public static final char MAX_HIGH_SURROGATE
      The maximum value of a Unicode high-surrogate code unit in the UTF-16 encoding, constant'\uDBFF'. A high-surrogate is also known as aleading-surrogate.
      Since:
      1.5
      See Also:
    • MIN_LOW_SURROGATE

      public static final char MIN_LOW_SURROGATE
      The minimum value of a Unicode low-surrogate code unit in the UTF-16 encoding, constant'\uDC00'. A low-surrogate is also known as atrailing-surrogate.
      Since:
      1.5
      See Also:
    • MAX_LOW_SURROGATE

      public static final char MAX_LOW_SURROGATE
      The maximum value of a Unicode low-surrogate code unit in the UTF-16 encoding, constant'\uDFFF'. A low-surrogate is also known as atrailing-surrogate.
      Since:
      1.5
      See Also:
    • MIN_SURROGATE

      public static final char MIN_SURROGATE
      The minimum value of a Unicode surrogate code unit in the UTF-16 encoding, constant'\uD800'.
      Since:
      1.5
      See Also:
    • MAX_SURROGATE

      public static final char MAX_SURROGATE
      The maximum value of a Unicode surrogate code unit in the UTF-16 encoding, constant'\uDFFF'.
      Since:
      1.5
      See Also:
    • MIN_SUPPLEMENTARY_CODE_POINT

      public static final int MIN_SUPPLEMENTARY_CODE_POINT
      The minimum value of a Unicode supplementary code point, constantU+10000.
      Since:
      1.5
      See Also:
    • MIN_CODE_POINT

      public static final int MIN_CODE_POINT
      The minimum value of a Unicode code point, constantU+0000.
      Since:
      1.5
      See Also:
    • MAX_CODE_POINT

      public static final int MAX_CODE_POINT
      The maximum value of a Unicode code point, constantU+10FFFF.
      Since:
      1.5
      See Also:
    • SIZE

      public static final int SIZE
      The number of bits used to represent achar value in unsigned binary form, constant16.
      Since:
      1.5
      See Also:
    • BYTES

      public static final int BYTES
      The number of bytes used to represent achar value in unsigned binary form.
      Since:
      1.8
      See Also:
  • Constructor Details

    • Character

      @Deprecated(since="9",forRemoval=true)public Character(char value)
      Deprecated, for removal: This API element is subject to removal in a future version.
      It is rarely appropriate to use this constructor. The static factoryvalueOf(char) is generally a better choice, as it is likely to yield significantly better space and time performance.
      Constructs a newly allocatedCharacter object that represents the specifiedchar value.
      Parameters:
      value - the value to be represented by theCharacter object.
  • Method Details

    • describeConstable

      public Optional<DynamicConstantDesc<Character>> describeConstable()
      Returns anOptional containing the nominal descriptor for this instance.
      Specified by:
      describeConstable in interface Constable
      Returns:
      anOptional describing theCharacter instance
      Since:
      15
    • valueOf

      public static Character valueOf(char c)
      Returns aCharacter instance representing the specifiedchar value. If a newCharacter instance is not required, this method should generally be used in preference to the constructorCharacter(char), as this method is likely to yield significantly better space and time performance by caching frequently requested values. This method will always cache values in the range '\u0000' to'\u007F', inclusive, and may cache other values outside of this range.
      Parameters:
      c - a char value.
      Returns:
      aCharacter instance representingc.
      Since:
      1.5
    • charValue

      public char charValue()
      Returns the value of thisCharacter object.
      Returns:
      the primitivechar value represented by this object.
    • hashCode

      public int hashCode()
      Returns a hash code for thisCharacter; equal to the result of invokingcharValue().
      Overrides:
      hashCode in class Object
      Returns:
      a hash code value for thisCharacter
      See Also:
    • hashCode

      public static int hashCode(char value)
      Returns a hash code for achar value; compatible withCharacter.hashCode().
      Parameters:
      value - Thechar for which to return a hash code.
      Returns:
      a hash code value for achar value.
      Since:
      1.8
    • equals

      public boolean equals(Object obj)
      Compares this object against the specified object. The result istrue if and only if the argument is notnull and is aCharacter object that represents the samechar value as this object.
      Overrides:
      equals in class Object
      Parameters:
      obj - the object to compare with.
      Returns:
      true if the objects are the same;false otherwise.
      See Also:
    • toString

      public String toString()
      Returns aString object representing thisCharacter's value. The result is a string of length 1 whose sole component is the primitivechar value represented by thisCharacter object.
      Overrides:
      toString in class Object
      Returns:
      a string representation of this object.
    • toString

      public static String toString(char c)
      Returns aString object representing the specifiedchar. The result is a string of length 1 consisting solely of the specifiedchar.
      API Note:
      This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use thetoString(int) method.
      Parameters:
      c - thechar to be converted
      Returns:
      the string representation of the specifiedchar
      Since:
      1.4
    • toString

      public static String toString(int codePoint)
      Returns aString object representing the specified character (Unicode code point). The result is a string of length 1 or 2, consisting solely of the specifiedcodePoint.
      Parameters:
      codePoint - thecodePoint to be converted
      Returns:
      the string representation of the specifiedcodePoint
      Throws:
      IllegalArgumentException - if the specifiedcodePoint is not avalid Unicode code point.
      Since:
      11
    • isValidCodePoint

      public static boolean isValidCodePoint(int codePoint)
      Determines whether the specified code point is a valid Unicode code point value.
      Parameters:
      codePoint - the Unicode code point to be tested
      Returns:
      true if the specified code point value is betweenMIN_CODE_POINT andMAX_CODE_POINT inclusive;false otherwise.
      Since:
      1.5
    • isBmpCodePoint

      public static boolean isBmpCodePoint(int codePoint)
      Determines whether the specified character (Unicode code point) is in theBasic Multilingual Plane (BMP). Such code points can be represented using a singlechar.
      Parameters:
      codePoint - the character (Unicode code point) to be tested
      Returns:
      true if the specified code point is betweenMIN_VALUE andMAX_VALUE inclusive;false otherwise.
      Since:
      1.7
    • 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:
      true if the specified code point is betweenMIN_SUPPLEMENTARY_CODE_POINT andMAX_CODE_POINT inclusive;false otherwise.
      Since:
      1.5
    • isHighSurrogate

      public static boolean isHighSurrogate(char ch)
      Determines if the givenchar value is a Unicode high-surrogate code unit (also known asleading-surrogate code unit).

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

      Parameters:
      ch - thechar value to be tested.
      Returns:
      true if thechar value is betweenMIN_HIGH_SURROGATE andMAX_HIGH_SURROGATE inclusive;false otherwise.
      Since:
      1.5
      See Also:
    • isLowSurrogate

      public static boolean isLowSurrogate(char ch)
      Determines if the givenchar value is a Unicode low-surrogate code unit (also known astrailing-surrogate code unit).

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

      Parameters:
      ch - thechar value to be tested.
      Returns:
      true if thechar value is betweenMIN_LOW_SURROGATE andMAX_LOW_SURROGATE inclusive;false otherwise.
      Since:
      1.5
      See Also:
    • isSurrogate

      public static boolean isSurrogate(char ch)
      Determines if the givenchar value is a Unicodesurrogate code unit.

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

      A char value is a surrogate code unit if and only if it is either alow-surrogate code unit or ahigh-surrogate code unit.

      Parameters:
      ch - thechar value to be tested.
      Returns:
      true if thechar value is betweenMIN_SURROGATE andMAX_SURROGATE inclusive;false otherwise.
      Since:
      1.7
    • isSurrogatePair

      public static boolean isSurrogatePair(char high, char low)
      Determines whether the specified pair ofchar values is a valid Unicode surrogate pair.

      This method is equivalent to the expression:

       isHighSurrogate(high) && isLowSurrogate(low)

      Parameters:
      high - the high-surrogate code value to be tested
      low - the low-surrogate code value to be tested
      Returns:
      true if the specified high and low-surrogate code values represent a valid surrogate pair;false otherwise.
      Since:
      1.5
    • charCount

      public static int charCount(int codePoint)
      Determines the number ofchar values needed to represent the specified character (Unicode code point). If the specified character is equal to or greater than 0x10000, then the method returns 2. Otherwise, the method returns 1.

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

      Parameters:
      codePoint - the character (Unicode code point) to be tested.
      Returns:
      2 if the character is a valid supplementary character; 1 otherwise.
      Since:
      1.5
      See Also:
    • toCodePoint

      public static int toCodePoint(char high, char low)
      Converts the specified surrogate pair to its supplementary code point value. This method does not validate the specified surrogate pair. The caller must validate it usingisSurrogatePair if necessary.
      Parameters:
      high - the high-surrogate code unit
      low - the low-surrogate code unit
      Returns:
      the supplementary code point composed from the specified surrogate pair.
      Since:
      1.5
    • codePointAt

      public static int codePointAt(CharSequence seq, int index)
      Returns the code point at the given index of theCharSequence. If thechar value at the given index in theCharSequence is in the high-surrogate range, the following index is less than the length of theCharSequence, and thechar value at the following index is in the low-surrogate range, then the supplementary code point corresponding to this surrogate pair is returned. Otherwise, thechar value at the given index is returned.
      Parameters:
      seq - a sequence ofchar values (Unicode code units)
      index - the index to thechar values (Unicode code units) inseq to be converted
      Returns:
      the Unicode code point at the given index
      Throws:
      NullPointerException - ifseq is null.
      IndexOutOfBoundsException - if the valueindex is negative or not less thanseq.length().
      Since:
      1.5
    • codePointAt

      public static int codePointAt(char[] a, int index)
      Returns the code point at the given index of thechar array. If thechar value at the given index in thechar array is in the high-surrogate range, the following index is less than the length of thechar array, and thechar value at the following index is in the low-surrogate range, then the supplementary code point corresponding to this surrogate pair is returned. Otherwise, thechar value at the given index is returned.
      Parameters:
      a - thechar array
      index - the index to thechar values (Unicode code units) in thechar array to be converted
      Returns:
      the Unicode code point at the given index
      Throws:
      NullPointerException - ifa is null.
      IndexOutOfBoundsException - if the valueindex is negative or not less than the length of thechar array.
      Since:
      1.5
    • codePointAt

      public static int codePointAt(char[] a, int index, int limit)
      Returns the code point at the given index of thechar array, where only array elements withindex less thanlimit can be used. If thechar value at the given index in thechar array is in the high-surrogate range, the following index is less than thelimit, and thechar value at the following index is in the low-surrogate range, then the supplementary code point corresponding to this surrogate pair is returned. Otherwise, thechar value at the given index is returned.
      Parameters:
      a - thechar array
      index - the index to thechar values (Unicode code units) in thechar array to be converted
      limit - the index after the last array element that can be used in thechar array
      Returns:
      the Unicode code point at the given index
      Throws:
      NullPointerException - ifa is null.
      IndexOutOfBoundsException - if theindex argument is negative or not less than thelimit argument, or if thelimit argument is negative or greater than the length of thechar array.
      Since:
      1.5
    • codePointBefore

      public static int codePointBefore(CharSequence seq, int index)
      Returns the code point preceding the given index of theCharSequence. If thechar value at(index - 1) in theCharSequence is in the low-surrogate range,(index - 2) is not negative, and thechar value at(index - 2) in theCharSequence is in the high-surrogate range, then the supplementary code point corresponding to this surrogate pair is returned. Otherwise, thechar value at(index - 1) is returned.
      Parameters:
      seq - theCharSequence instance
      index - the index following the code point that should be returned
      Returns:
      the Unicode code point value before the given index.
      Throws:
      NullPointerException - ifseq is null.
      IndexOutOfBoundsException - if theindex argument is less than 1 or greater thanseq.length().
      Since:
      1.5
    • codePointBefore

      public static int codePointBefore(char[] a, int index)
      Returns the code point preceding the given index of thechar array. If thechar value at(index - 1) in thechar array is in the low-surrogate range,(index - 2) is not negative, and thechar value at(index - 2) in thechar array is in the high-surrogate range, then the supplementary code point corresponding to this surrogate pair is returned. Otherwise, thechar value at(index - 1) is returned.
      Parameters:
      a - thechar array
      index - the index following the code point that should be returned
      Returns:
      the Unicode code point value before the given index.
      Throws:
      NullPointerException - ifa is null.
      IndexOutOfBoundsException - if theindex argument is less than 1 or greater than the length of thechar array
      Since:
      1.5
    • codePointBefore

      public static int codePointBefore(char[] a, int index, int start)
      Returns the code point preceding the given index of thechar array, where only array elements withindex greater than or equal tostart can be used. If thechar value at(index - 1) in thechar array is in the low-surrogate range,(index - 2) is not less thanstart, and thechar value at(index - 2) in thechar array is in the high-surrogate range, then the supplementary code point corresponding to this surrogate pair is returned. Otherwise, thechar value at(index - 1) is returned.
      Parameters:
      a - thechar array
      index - the index following the code point that should be returned
      start - the index of the first array element in thechar array
      Returns:
      the Unicode code point value before the given index.
      Throws:
      NullPointerException - ifa is null.
      IndexOutOfBoundsException - if theindex argument is not greater than thestart argument or is greater than the length of thechar array, or if thestart argument is negative or not less than the length of thechar array.
      Since:
      1.5
    • highSurrogate

      public static char highSurrogate(int codePoint)
      Returns the leading surrogate (a high surrogate code unit) of the surrogate pair representing the specified supplementary character (Unicode code point) in the UTF-16 encoding. If the specified character is not asupplementary character, an unspecifiedchar is returned.

      IfisSupplementaryCodePoint(x) istrue, thenisHighSurrogate(highSurrogate(x)) andtoCodePoint(highSurrogate(x),lowSurrogate(x)) == x are also alwaystrue.

      Parameters:
      codePoint - a supplementary character (Unicode code point)
      Returns:
      the leading surrogate code unit used to represent the character in the UTF-16 encoding
      Since:
      1.7
    • lowSurrogate

      public static char lowSurrogate(int codePoint)
      Returns the trailing surrogate (a low surrogate code unit) of the surrogate pair representing the specified supplementary character (Unicode code point) in the UTF-16 encoding. If the specified character is not asupplementary character, an unspecifiedchar is returned.

      IfisSupplementaryCodePoint(x) istrue, thenisLowSurrogate(lowSurrogate(x)) andtoCodePoint(highSurrogate(x), lowSurrogate(x)) == x are also alwaystrue.

      Parameters:
      codePoint - a supplementary character (Unicode code point)
      Returns:
      the trailing surrogate code unit used to represent the character in the UTF-16 encoding
      Since:
      1.7
    • toChars

      public static int toChars(int codePoint, char[] dst, int dstIndex)
      Converts the specified character (Unicode code point) to its UTF-16 representation. If the specified code point is a BMP (Basic Multilingual Plane or Plane 0) value, the same value is stored indst[dstIndex], and 1 is returned. If the specified code point is a supplementary character, its surrogate values are stored indst[dstIndex] (high-surrogate) anddst[dstIndex+1] (low-surrogate), and 2 is returned.
      Parameters:
      codePoint - the character (Unicode code point) to be converted.
      dst - an array ofchar in which thecodePoint's UTF-16 value is stored.
      dstIndex - the start index into thedst array where the converted value is stored.
      Returns:
      1 if the code point is a BMP code point, 2 if the code point is a supplementary code point.
      Throws:
      IllegalArgumentException - if the specifiedcodePoint is not a valid Unicode code point.
      NullPointerException - if the specifieddst is null.
      IndexOutOfBoundsException - ifdstIndex is negative or not less thandst.length, or ifdst atdstIndex doesn't have enough array element(s) to store the resultingchar value(s). (IfdstIndex is equal todst.length-1 and the specifiedcodePoint is a supplementary character, the high-surrogate value is not stored indst[dstIndex].)
      Since:
      1.5
    • toChars

      public static char[] toChars(int codePoint)
      Converts the specified character (Unicode code point) to its UTF-16 representation stored in achar array. If the specified code point is a BMP (Basic Multilingual Plane or Plane 0) value, the resultingchar array has the same value ascodePoint. If the specified code point is a supplementary code point, the resultingchar array has the corresponding surrogate pair.
      Parameters:
      codePoint - a Unicode code point
      Returns:
      achar array havingcodePoint's UTF-16 representation.
      Throws:
      IllegalArgumentException - if the specifiedcodePoint is not a valid Unicode code point.
      Since:
      1.5
    • codePointCount

      public static int codePointCount(CharSequence seq, int beginIndex, int endIndex)
      Returns the number of Unicode code points in the text range of the specified char sequence. The text range begins at the specifiedbeginIndex and extends to thechar at indexendIndex - 1. Thus the length (inchars) of the text range isendIndex-beginIndex. Unpaired surrogates within the text range count as one code point each.
      Parameters:
      seq - the char sequence
      beginIndex - the index to the firstchar of the text range.
      endIndex - the index after the lastchar of the text range.
      Returns:
      the number of Unicode code points in the specified text range
      Throws:
      NullPointerException - ifseq is null.
      IndexOutOfBoundsException - if thebeginIndex is negative, orendIndex is larger than the length of the given sequence, orbeginIndex is larger thanendIndex.
      Since:
      1.5
    • codePointCount

      public static int codePointCount(char[] a, int offset, int count)
      Returns the number of Unicode code points in a subarray of thechar array argument. Theoffset argument is the index of the firstchar of the subarray and thecount argument specifies the length of the subarray inchars. Unpaired surrogates within the subarray count as one code point each.
      Parameters:
      a - thechar array
      offset - the index of the firstchar in the givenchar array
      count - the length of the subarray inchars
      Returns:
      the number of Unicode code points in the specified subarray
      Throws:
      NullPointerException - ifa is null.
      IndexOutOfBoundsException - ifoffset orcount is negative, or ifoffset + count is larger than the length of the given array.
      Since:
      1.5
    • offsetByCodePoints

      public static int offsetByCodePoints(CharSequence seq, int index, int codePointOffset)
      Returns the index within the given char sequence that is offset from the givenindex bycodePointOffset code points. Unpaired surrogates within the text range given byindex andcodePointOffset count as one code point each.
      Parameters:
      seq - the char sequence
      index - the index to be offset
      codePointOffset - the offset in code points
      Returns:
      the index within the char sequence
      Throws:
      NullPointerException - ifseq is null.
      IndexOutOfBoundsException - ifindex is negative or larger than the length of the char sequence, or ifcodePointOffset is positive and the subsequence starting withindex has fewer thancodePointOffset code points, or ifcodePointOffset is negative and the subsequence beforeindex has fewer than the absolute value ofcodePointOffset code points.
      Since:
      1.5
    • offsetByCodePoints

      public static int offsetByCodePoints(char[] a, int start, int count, int index, int codePointOffset)
      Returns the index within the givenchar subarray that is offset from the givenindex bycodePointOffset code points. Thestart andcount arguments specify a subarray of thechar array. Unpaired surrogates within the text range given byindex andcodePointOffset count as one code point each.
      Parameters:
      a - thechar array
      start - the index of the firstchar of the subarray
      count - the length of the subarray inchars
      index - the index to be offset
      codePointOffset - the offset in code points
      Returns:
      the index within the subarray
      Throws:
      NullPointerException - ifa is null.
      IndexOutOfBoundsException - ifstart orcount is negative, or ifstart + count is larger than the length of the given array, or ifindex is less thanstart or larger thenstart + count, or ifcodePointOffset is positive and the text range starting withindex and ending withstart + count - 1 has fewer thancodePointOffset code points, or ifcodePointOffset is negative and the text range starting withstart and ending withindex - 1 has fewer than the absolute value ofcodePointOffset code points.
      Since:
      1.5
    • isLowerCase

      public static boolean isLowerCase(char ch)
      Determines if the specified character is a lowercase character.

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

      The following are examples of lowercase characters:

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

      Many other Unicode characters are lowercase too.

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

      Parameters:
      ch - the character to be tested.
      Returns:
      true if the character is lowercase;false otherwise.
      See Also:
    • isLowerCase

      public static boolean isLowerCase(int codePoint)
      Determines if the specified character (Unicode code point) is a lowercase character.

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

      The following are examples of lowercase characters:

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

      Many other Unicode characters are lowercase too.

      Parameters:
      codePoint - the character (Unicode code point) to be tested.
      Returns:
      true if the character is lowercase;false otherwise.
      Since:
      1.5
      See Also:
    • isUpperCase

      public static boolean isUpperCase(char ch)
      Determines if the specified character is an uppercase character.

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

      The following are examples of uppercase characters:

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

      Many other Unicode characters are uppercase too.

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

      Parameters:
      ch - the character to be tested.
      Returns:
      true if the character is uppercase;false otherwise.
      Since:
      1.0
      See Also:
    • isUpperCase

      public static boolean isUpperCase(int codePoint)
      Determines if the specified character (Unicode code point) is an uppercase character.

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

      The following are examples of uppercase characters:

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

      Many other Unicode characters are uppercase too.

      Parameters:
      codePoint - the character (Unicode code point) to be tested.
      Returns:
      true if the character is uppercase;false otherwise.
      Since:
      1.5
      See Also:
    • isTitleCase

      public static boolean isTitleCase(char ch)
      Determines if the specified character is a titlecase character.

      A character is a titlecase character if its general category type, provided byCharacter.getType(ch), isTITLECASE_LETTER.

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

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

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

      Many other Unicode characters are titlecase too.

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

      Parameters:
      ch - the character to be tested.
      Returns:
      true if the character is titlecase;false otherwise.
      Since:
      1.0.2
      See Also:
    • isTitleCase

      public static boolean isTitleCase(int codePoint)
      Determines if the specified character (Unicode code point) is a titlecase character.

      A character is a titlecase character if its general category type, provided bygetType(codePoint), isTITLECASE_LETTER.

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

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

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

      Many other Unicode characters are titlecase too.

      Parameters:
      codePoint - the character (Unicode code point) to be tested.
      Returns:
      true if the character is titlecase;false otherwise.
      Since:
      1.5
      See Also:
    • isDigit

      public static boolean isDigit(char ch)
      Determines if the specified character is a digit.

      A character is a digit if its general category type, provided byCharacter.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
      Many other character ranges contain digits as well.

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

      Parameters:
      ch - the character to be tested.
      Returns:
      true if the character is a digit;false otherwise.
      See Also:
    • isDigit

      public static boolean isDigit(int codePoint)
      Determines if the specified character (Unicode code point) is a digit.

      A character is a digit if its general category type, provided bygetType(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
      Many other character ranges contain digits as well.

      Parameters:
      codePoint - the character (Unicode code point) to be tested.
      Returns:
      true if the character is a digit;false otherwise.
      Since:
      1.5
      See Also:
    • isDefined

      public static boolean isDefined(char ch)
      Determines if a character is defined in Unicode.

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

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

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

      Parameters:
      ch - the character to be tested
      Returns:
      true if the character has a defined meaning in Unicode;false otherwise.
      Since:
      1.0.2
      See Also:
    • isDefined

      public static boolean isDefined(int codePoint)
      Determines if a character (Unicode code point) is defined in Unicode.

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

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

      Parameters:
      codePoint - the character (Unicode code point) to be tested.
      Returns:
      true if the character has a defined meaning in Unicode;false otherwise.
      Since:
      1.5
      See Also:
    • isLetter

      public static boolean isLetter(char ch)
      Determines if the specified character is a letter.

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

      • UPPERCASE_LETTER
      • LOWERCASE_LETTER
      • TITLECASE_LETTER
      • MODIFIER_LETTER
      • OTHER_LETTER
      Not all letters have case. Many characters are letters but are neither uppercase nor lowercase nor titlecase.

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

      Parameters:
      ch - the character to be tested.
      Returns:
      true if the character is a letter;false otherwise.
      See Also:
    • isLetter

      public static boolean isLetter(int codePoint)
      Determines if the specified character (Unicode code point) is a letter.

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

      • UPPERCASE_LETTER
      • LOWERCASE_LETTER
      • TITLECASE_LETTER
      • MODIFIER_LETTER
      • OTHER_LETTER
      Not all letters have case. Many characters are letters but are neither uppercase nor lowercase nor titlecase.

      Parameters:
      codePoint - the character (Unicode code point) to be tested.
      Returns:
      true if the character is a letter;false otherwise.
      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 eitherCharacter.isLetter(char ch) orCharacter.isDigit(char ch) returnstrue for the character.

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

      Parameters:
      ch - the character to be tested.
      Returns:
      true if the character is a letter or digit;false otherwise.
      Since:
      1.0.2
      See Also:
    • isLetterOrDigit

      public static boolean isLetterOrDigit(int codePoint)
      Determines if the specified character (Unicode code point) is a letter or digit.

      A character is considered to be a letter or digit if eitherisLetter(codePoint) orisDigit(codePoint) returnstrue for the character.

      Parameters:
      codePoint - the character (Unicode code point) to be tested.
      Returns:
      true if the character is a letter or digit;false otherwise.
      Since:
      1.5
      See Also:
    • isJavaLetter

      @Deprecated(since="1.1")public static boolean isJavaLetter(char ch)
      Deprecated.
      Replaced by isJavaIdentifierStart(char).
      Determines if the specified character is permissible as the first character in a Java identifier.

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

      • isLetter(ch) returnstrue
      • getType(ch) returnsLETTER_NUMBER
      • ch is a currency symbol (such as'$')
      • ch is a connecting punctuation character (such as'_').

      Parameters:
      ch - the character to be tested.
      Returns:
      true if the character may start a Java identifier;false otherwise.
      Since:
      1.0.2
      See Also:
    • isJavaLetterOrDigit

      @Deprecated(since="1.1")public static boolean isJavaLetterOrDigit(char ch)
      Deprecated.
      Replaced by isJavaIdentifierPart(char).
      Determines if the specified character may be part of a Java identifier as other than the first character.

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

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

      Parameters:
      ch - the character to be tested.
      Returns:
      true if the character may be part of a Java identifier;false otherwise.
      Since:
      1.0.2
      See Also:
    • isAlphabetic

      public static boolean isAlphabetic(int codePoint)
      Determines if the specified character (Unicode code point) is alphabetic.

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

      • UPPERCASE_LETTER
      • LOWERCASE_LETTER
      • TITLECASE_LETTER
      • MODIFIER_LETTER
      • OTHER_LETTER
      • LETTER_NUMBER
      or it has contributory property Other_Alphabetic as defined by the Unicode Standard.

      Parameters:
      codePoint - the character (Unicode code point) to be tested.
      Returns:
      true if the character is a Unicode alphabet character,false otherwise.
      Since:
      1.7
    • isIdeographic

      public static boolean isIdeographic(int codePoint)
      Determines if the specified character (Unicode code point) is a CJKV (Chinese, Japanese, Korean and Vietnamese) ideograph, as defined by the Unicode Standard.
      Parameters:
      codePoint - the character (Unicode code point) to be tested.
      Returns:
      true if the character is a Unicode ideograph character,false otherwise.
      Since:
      1.7
    • isJavaIdentifierStart

      public static boolean isJavaIdentifierStart(char ch)
      Determines if the specified character is permissible as the first character in a Java identifier.

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

      • isLetter(ch) returnstrue
      • getType(ch) returnsLETTER_NUMBER
      • ch is a currency symbol (such as'$')
      • ch is a connecting punctuation character (such as'_').

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

      Parameters:
      ch - the character to be tested.
      Returns:
      true if the character may start a Java identifier;false otherwise.
      Since:
      1.1
      See Also:
    • isJavaIdentifierStart

      public static boolean isJavaIdentifierStart(int codePoint)
      Determines if the character (Unicode code point) is permissible as the first character in a Java identifier.

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

      • isLetter(codePoint) returnstrue
      • getType(codePoint) returnsLETTER_NUMBER
      • the referenced character is a currency symbol (such as'$')
      • the referenced character is a connecting punctuation character (such as'_').

      Parameters:
      codePoint - the character (Unicode code point) to be tested.
      Returns:
      true if the character may start a Java identifier;false otherwise.
      Since:
      1.5
      See Also:
    • isJavaIdentifierPart

      public static boolean isJavaIdentifierPart(char ch)
      Determines if the specified character may be part of a Java identifier as other than the first character.

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

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

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

      Parameters:
      ch - the character to be tested.
      Returns:
      true if the character may be part of a Java identifier;false otherwise.
      Since:
      1.1
      See Also:
    • isJavaIdentifierPart

      public static boolean isJavaIdentifierPart(int codePoint)
      Determines if the character (Unicode code point) may be part of a Java identifier as other than the first character.

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

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

      Parameters:
      codePoint - the character (Unicode code point) to be tested.
      Returns:
      true if the character may be part of a Java identifier;false otherwise.
      Since:
      1.5
      See Also:
    • isUnicodeIdentifierStart

      public static boolean isUnicodeIdentifierStart(char ch)
      Determines if the specified character is permissible as the first character in a Unicode identifier.

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

      This method conforms to UAX31-R1: Default Identifiers requirement of the Unicode Standard, with the following profile of UAX31:

       Start := ID_Start + 'VERTICAL TILDE' (U+2E2F)
      'VERTICAL TILDE' is added toStart for backward compatibility.

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

      Parameters:
      ch - the character to be tested.
      Returns:
      true if the character may start a Unicode identifier;false otherwise.
      Since:
      1.1
      External Specifications
      See Also:
    • isUnicodeIdentifierStart

      public static boolean isUnicodeIdentifierStart(int codePoint)
      Determines if the specified character (Unicode code point) is permissible as the first character in a Unicode identifier.

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

      This method conforms to UAX31-R1: Default Identifiers requirement of the Unicode Standard, with the following profile of UAX31:

       Start := ID_Start + 'VERTICAL TILDE' (U+2E2F)
      'VERTICAL TILDE' is added toStart for backward compatibility.

      Parameters:
      codePoint - the character (Unicode code point) to be tested.
      Returns:
      true if the character may start a Unicode identifier;false otherwise.
      Since:
      1.5
      External Specifications
      See Also:
    • isUnicodeIdentifierPart

      public static boolean isUnicodeIdentifierPart(char ch)
      Determines if the specified character may be part of a Unicode identifier as other than the first character.

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

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

      This method conforms to UAX31-R1: Default Identifiers requirement of the Unicode Standard, with the following profile of UAX31:

       Continue := Start + ID_Continue + ignorable Medial := empty ignorable := isIdentifierIgnorable(char) returns true for the character
      ignorable is added toContinue for backward compatibility.

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

      Parameters:
      ch - the character to be tested.
      Returns:
      true if the character may be part of a Unicode identifier;false otherwise.
      Since:
      1.1
      External Specifications
      See Also:
    • isUnicodeIdentifierPart

      public static boolean isUnicodeIdentifierPart(int codePoint)
      Determines if the specified character (Unicode code point) may be part of a Unicode identifier as other than the first character.

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

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

      This method conforms to UAX31-R1: Default Identifiers requirement of the Unicode Standard, with the following profile of UAX31:

       Continue := Start + ID_Continue + ignorable Medial := empty ignorable := isIdentifierIgnorable(int) returns true for the character
      ignorable is added toContinue for backward compatibility.

      Parameters:
      codePoint - the character (Unicode code point) to be tested.
      Returns:
      true if the character may be part of a Unicode identifier;false otherwise.
      Since:
      1.5
      External Specifications
      See Also:
    • isIdentifierIgnorable

      public static boolean isIdentifierIgnorable(char ch)
      Determines if the specified character should be regarded as an ignorable character in a Java identifier or a Unicode identifier.

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

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

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

      Parameters:
      ch - the character to be tested.
      Returns:
      true if the character is an ignorable control character that may be part of a Java or Unicode identifier;false otherwise.
      Since:
      1.1
      See Also:
    • isIdentifierIgnorable

      public static boolean isIdentifierIgnorable(int codePoint)
      Determines if the specified character (Unicode code point) should be regarded as an ignorable character in a Java identifier or a Unicode identifier.

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

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

      Parameters:
      codePoint - the character (Unicode code point) to be tested.
      Returns:
      true if the character is an ignorable control character that may be part of a Java or Unicode identifier;false otherwise.
      Since:
      1.5
      See Also:
    • 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 theEmoji property, defined in Unicode Emoji (Technical Standard #51).

      Parameters:
      codePoint - the character (Unicode code point) to be tested.
      Returns:
      true if the character is an Emoji;false otherwise.
      Since:
      21
    • isEmojiPresentation

      public static boolean isEmojiPresentation(int codePoint)
      Determines if the specified character (Unicode code point) has the Emoji Presentation property by default.

      A character is considered to have the Emoji Presentation property if and only if it has theEmoji_Presentation property, defined in Unicode Emoji (Technical Standard #51).

      Parameters:
      codePoint - the character (Unicode code point) to be tested.
      Returns:
      true if the character has the Emoji Presentation property;false otherwise.
      Since:
      21
    • isEmojiModifier

      public static boolean isEmojiModifier(int codePoint)
      Determines if the specified character (Unicode code point) is an Emoji Modifier.

      A character is considered to be an Emoji Modifier if and only if it has theEmoji_Modifier property, defined in Unicode Emoji (Technical Standard #51).

      Parameters:
      codePoint - the character (Unicode code point) to be tested.
      Returns:
      true if the character is an Emoji Modifier;false otherwise.
      Since:
      21
    • isEmojiModifierBase

      public static boolean isEmojiModifierBase(int codePoint)
      Determines if the specified character (Unicode code point) is an Emoji Modifier Base.

      A character is considered to be an Emoji Modifier Base if and only if it has theEmoji_Modifier_Base property, defined in Unicode Emoji (Technical Standard #51).

      Parameters:
      codePoint - the character (Unicode code point) to be tested.
      Returns:
      true if the character is an Emoji Modifier Base;false otherwise.
      Since:
      21
    • isEmojiComponent

      public static boolean isEmojiComponent(int codePoint)
      Determines if the specified character (Unicode code point) is an Emoji Component.

      A character is considered to be an Emoji Component if and only if it has theEmoji_Component property, defined in Unicode Emoji (Technical Standard #51).

      Parameters:
      codePoint - the character (Unicode code point) to be tested.
      Returns:
      true if the character is an Emoji Component;false otherwise.
      Since:
      21
    • isExtendedPictographic

      public static boolean isExtendedPictographic(int codePoint)
      Determines if the specified character (Unicode code point) is an Extended Pictographic.

      A character is considered to be an Extended Pictographic if and only if it has theExtended_Pictographic property, defined in Unicode Emoji (Technical Standard #51).

      Parameters:
      codePoint - the character (Unicode code point) to be tested.
      Returns:
      true if the character is an Extended Pictographic;false otherwise.
      Since:
      21
    • toLowerCase

      public static char toLowerCase(char ch)
      Converts the character argument to lowercase using case mapping information from the UnicodeData file.

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

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

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

      Parameters:
      ch - the character to be converted.
      Returns:
      the lowercase equivalent of the character, if any; otherwise, the character itself.
      See Also:
    • toLowerCase

      public static int toLowerCase(int codePoint)
      Converts the character (Unicode code point) argument to lowercase using case mapping information from the UnicodeData file.

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

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

      Parameters:
      codePoint - the character (Unicode code point) to be converted.
      Returns:
      the lowercase equivalent of the character (Unicode code point), if any; otherwise, the character itself.
      Since:
      1.5
      See Also:
    • toUpperCase

      public static char toUpperCase(char ch)
      Converts the character argument to uppercase using case mapping information from the UnicodeData file.

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

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

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

      Parameters:
      ch - the character to be converted.
      Returns:
      the uppercase equivalent of the character, if any; otherwise, the character itself.
      See Also:
    • toUpperCase

      public static int toUpperCase(int codePoint)
      Converts the character (Unicode code point) argument to uppercase using case mapping information from the UnicodeData file.

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

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

      Parameters:
      codePoint - the character (Unicode code point) to be converted.
      Returns:
      the uppercase equivalent of the character, if any; otherwise, the character itself.
      Since:
      1.5
      See Also:
    • toTitleCase

      public static char toTitleCase(char ch)
      Converts the character argument to titlecase using case mapping information from the UnicodeData file. If a character has no explicit titlecase mapping and is not itself a titlecase char according to UnicodeData, then the uppercase mapping is returned as an equivalent titlecase mapping. If thechar argument is already a titlecasechar, the samechar value will be returned.

      Note thatCharacter.isTitleCase(Character.toTitleCase(ch)) does not always returntrue for some ranges of characters.

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

      Parameters:
      ch - the character to be converted.
      Returns:
      the titlecase equivalent of the character, if any; otherwise, the character itself.
      Since:
      1.0.2
      See Also:
    • toTitleCase

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

      Note thatCharacter.isTitleCase(Character.toTitleCase(codePoint)) does not always returntrue for some ranges of characters.

      Parameters:
      codePoint - the character (Unicode code point) to be converted.
      Returns:
      the titlecase equivalent of the character, if any; otherwise, the character itself.
      Since:
      1.5
      See Also:
    • digit

      public static int digit(char ch, int radix)
      Returns the numeric value of the characterch in the specified radix.

      If the radix is not in the rangeMIN_RADIXradixMAX_RADIX or if the value ofch is not a valid digit in the specified radix,-1 is returned. A character is a valid digit if at least one of the following is true:

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

      Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use thedigit(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:
    • digit

      public static int digit(int codePoint, int radix)
      Returns the numeric value of the specified character (Unicode code point) in the specified radix.

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

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

      Parameters:
      codePoint - the character (Unicode code point) to be converted.
      radix - the radix.
      Returns:
      the numeric value represented by the character in the specified radix.
      Since:
      1.5
      See Also:
    • getNumericValue

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

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

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

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

      Parameters:
      ch - the character to be converted.
      Returns:
      the numeric value of the character, as a nonnegativeint value; -2 if the character has a numeric value but the value can not be represented as a nonnegativeint value; -1 if the character has no numeric value.
      Since:
      1.1
      See Also:
    • getNumericValue

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

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

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

      Parameters:
      codePoint - the character (Unicode code point) to be converted.
      Returns:
      the numeric value of the character, as a nonnegativeint value; -2 if the character has a numeric value but the value can not be represented as a nonnegativeint value; -1 if the character has no numeric value.
      Since:
      1.5
      See Also:
    • isSpace

      @Deprecated(since="1.1")public static boolean isSpace(char ch)
      Deprecated.
      Replaced by isWhitespace(char).
      Determines if the specified character is ISO-LATIN-1 white space. This method returnstrue for the following five characters only:
      truechars
      CharacterCodeName
      '\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:
      true if the character is ISO-LATIN-1 white space;false otherwise.
      See Also:
    • isSpaceChar

      public static boolean isSpaceChar(char ch)
      Determines if the specified character is a Unicode space character. A character is considered to be a space character if and only if it is specified to be a space character by the Unicode Standard. This method returns true if the character's general category type is any of the following:
      • SPACE_SEPARATOR
      • LINE_SEPARATOR
      • PARAGRAPH_SEPARATOR

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

      Parameters:
      ch - the character to be tested.
      Returns:
      true if the character is a space character;false otherwise.
      Since:
      1.1
      See Also:
    • isSpaceChar

      public static boolean isSpaceChar(int codePoint)
      Determines if the specified character (Unicode code point) is a Unicode space character. A character is considered to be a space character if and only if it is specified to be a space character by the Unicode Standard. This method returns true if the character's general category type is any of the following:
      Parameters:
      codePoint - the character (Unicode code point) to be tested.
      Returns:
      true if the character is a space character;false otherwise.
      Since:
      1.5
      See Also:
    • isWhitespace

      public static boolean isWhitespace(char ch)
      Determines if the specified character is white space according to Java. A character is a Java whitespace character if and only if it satisfies one of the following criteria:
      • It is a Unicode space character (SPACE_SEPARATOR,LINE_SEPARATOR, orPARAGRAPH_SEPARATOR) but is not also a non-breaking space ('\u00A0','\u2007','\u202F').
      • It is'\t', U+0009 HORIZONTAL TABULATION.
      • It is'\n', U+000A LINE FEED.
      • It is'\u000B', U+000B VERTICAL TABULATION.
      • It is'\f', U+000C FORM FEED.
      • It is'\r', U+000D CARRIAGE RETURN.
      • It is'\u001C', U+001C FILE SEPARATOR.
      • It is'\u001D', U+001D GROUP SEPARATOR.
      • It is'\u001E', U+001E RECORD SEPARATOR.
      • It is'\u001F', U+001F UNIT SEPARATOR.

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

      Parameters:
      ch - the character to be tested.
      Returns:
      true if the character is a Java whitespace character;false otherwise.
      Since:
      1.1
      See Also:
    • isWhitespace

      public static boolean isWhitespace(int codePoint)
      Determines if the specified character (Unicode code point) is white space according to Java. A character is a Java whitespace character if and only if it satisfies one of the following criteria:
      • It is a Unicode space character (SPACE_SEPARATOR,LINE_SEPARATOR, orPARAGRAPH_SEPARATOR) but is not also a non-breaking space ('\u00A0','\u2007','\u202F').
      • It is'\t', U+0009 HORIZONTAL TABULATION.
      • It is'\n', U+000A LINE FEED.
      • It is'\u000B', U+000B VERTICAL TABULATION.
      • It is'\f', U+000C FORM FEED.
      • It is'\r', U+000D CARRIAGE RETURN.
      • It is'\u001C', U+001C FILE SEPARATOR.
      • It is'\u001D', U+001D GROUP SEPARATOR.
      • It is'\u001E', U+001E RECORD SEPARATOR.
      • It is'\u001F', U+001F UNIT SEPARATOR.
      Parameters:
      codePoint - the character (Unicode code point) to be tested.
      Returns:
      true if the character is a Java whitespace character;false otherwise.
      Since:
      1.5
      See Also:
    • isISOControl

      public static boolean isISOControl(char ch)
      Determines if the specified character is an ISO control character. A character is considered to be an ISO control character if its code is in the range'\u0000' through'\u001F' or in the range'\u007F' through'\u009F'.

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

      Parameters:
      ch - the character to be tested.
      Returns:
      true if the character is an ISO control character;false otherwise.
      Since:
      1.1
      See Also:
    • isISOControl

      public static boolean isISOControl(int codePoint)
      Determines if the referenced character (Unicode code point) is an ISO control character. A character is considered to be an ISO control character if its code is in the range'\u0000' through'\u001F' or in the range'\u007F' through'\u009F'.
      Parameters:
      codePoint - the character (Unicode code point) to be tested.
      Returns:
      true if the character is an ISO control character;false otherwise.
      Since:
      1.5
      See Also:
    • getType

      public static int getType(char ch)
      Returns a value indicating a character's general category.

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

      Parameters:
      ch - the character to be tested.
      Returns:
      a value of typeint representing the character's general category.
      Since:
      1.1
      See Also:
    • getType

    • forDigit

      public static char forDigit(int digit, int radix)
      Determines the character representation for a specific digit in the specified radix. If the value ofradix is not a valid radix, or the value ofdigit is not a valid digit in the specified radix, the null character ('\u0000') is returned.

      Theradix argument is valid if it is greater than or equal toMIN_RADIX and less than or equal toMAX_RADIX. Thedigit argument is valid if0 <= digit < radix.

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

      Parameters:
      digit - the number to convert to a character.
      radix - the radix.
      Returns:
      thechar representation of the specified digit in the specified radix.
      See Also:
    • getDirectionality

      public static byte getDirectionality(char ch)
      Returns the Unicode directionality property for the given character. Character directionality is used to calculate the visual ordering of text. The directionality value of undefinedchar values isDIRECTIONALITY_UNDEFINED.

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

      Parameters:
      ch -char for which the directionality property is requested.
      Returns:
      the directionality property of thechar value.
      Since:
      1.4
      See Also:
    • getDirectionality

      public static byte getDirectionality(int codePoint)
      Returns the Unicode directionality property for the given character (Unicode code point). Character directionality is used to calculate the visual ordering of text. The directionality value of undefined character isDIRECTIONALITY_UNDEFINED.
      Parameters:
      codePoint - the character (Unicode code point) for which the directionality property is requested.
      Returns:
      the directionality property of the character.
      Since:
      1.5
      See Also:
    • isMirrored

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

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

      Parameters:
      ch -char for which the mirrored property is requested
      Returns:
      true if the char is mirrored,false if thechar is not mirrored or is not defined.
      Since:
      1.4
    • isMirrored

      public static boolean isMirrored(int codePoint)
      Determines whether the specified character (Unicode code point) is mirrored according to the Unicode specification. Mirrored characters should have their glyphs horizontally mirrored when displayed in text that is right-to-left. For example,'\u0028' LEFT PARENTHESIS is semantically defined to be anopening parenthesis. This will appear as a "(" in text that is left-to-right but as a ")" in text that is right-to-left.
      Parameters:
      codePoint - the character (Unicode code point) to be tested.
      Returns:
      true if the character is mirrored,false if the character is not mirrored or is not defined.
      Since:
      1.5
    • compareTo

      public int compareTo(Character anotherCharacter)
      Compares twoCharacter objects numerically.
      Specified by:
      compareTo in interface Comparable<Character>
      Parameters:
      anotherCharacter - theCharacter to be compared.
      Returns:
      the value0 if the argumentCharacter is equal to thisCharacter; a value less than0 if thisCharacter is numerically less than theCharacter argument; and a value greater than0 if thisCharacter is numerically greater than theCharacter argument (unsigned comparison). Note that this is strictly a numerical comparison; it is not locale-dependent.
      Since:
      1.2
    • compare

      public static int compare(char x, char y)
      Compares twochar values numerically. The value returned is identical to what would be returned by:
          Character.valueOf(x).compareTo(Character.valueOf(y))
      Parameters:
      x - the firstchar to compare
      y - the secondchar to compare
      Returns:
      the value0 ifx == y; a value less than0 ifx < y; and a value greater than0 ifx > y
      Since:
      1.7
    • reverseBytes

      public static char reverseBytes(char ch)
      Returns the value obtained by reversing the order of the bytes in the specifiedchar value.
      Parameters:
      ch - Thechar of which to reverse the byte order.
      Returns:
      the value obtained by reversing (or, equivalently, swapping) the bytes in the specifiedchar value.
      Since:
      1.5
    • getName

      public static String getName(int codePoint)
      Returns the name of the specified charactercodePoint, or null if the code point isunassigned.

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

      Character.UnicodeBlock.of(codePoint).toString().replace('_', ' ') + " " + Integer.toHexString(codePoint).toUpperCase(Locale.ROOT);
      For thecodePoints in theUnicodeData file, the name returned by this method follows the naming scheme in the "Unicode Name Property" section of the Unicode Standard. For other code points, such as Hangul/Ideographs, The name generation rule above differs from the one defined in the Unicode Standard.

      Parameters:
      codePoint - the character (Unicode code point)
      Returns:
      the name of the specified character, or null if the code point is unassigned.
      Throws:
      IllegalArgumentException - if the specifiedcodePoint is not a valid Unicode code point.
      Since:
      1.7
    • codePointOf

      public static int codePointOf(String name)
      Returns the code point value of the Unicode character specified by the given character name.

      If a character is not assigned a name by theUnicodeData file (part of the Unicode Character Database maintained by the Unicode Consortium), its name is defined as the result of the expression:

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

      Thename matching is case insensitive, with any leading and trailing whitespace character removed. For the code points in theUnicodeData file, this method recognizes the name which conforms to the name defined in the "Unicode Name Property" section in the Unicode Standard. For other code points, this method recognizes the name generated withgetName(int) method.

      Parameters:
      name - the character name
      Returns:
      the code point value of the character specified by its name.
      Throws:
      IllegalArgumentException - if the specifiedname is not a valid character name.
      NullPointerException - ifname isnull
      Since:
      9