Module java.base
Package java.lang

Class Character

  • All Implemented Interfaces:
    Serializable,Comparable<Character>

    public final classCharacterextendsObjectimplementsSerializable,Comparable<Character>
    TheCharacter class wraps a value of the primitive typechar in an object. An object of classCharacter 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.

    The Java SE 11 Platform uses character information from version 10.0 of the Unicode Standard, with two extensions. First, the Java SE 11 Platform allows an implementation of classCharacter to use the code points in the range ofU+9FEB toU+9FEF from the Unicode Standard version 11.0, in order for the class to allow the "Implementation Level 2" of the Chinese GB18030-2022 standard. Second, the Java SE 11 Platform allows an implementation of classCharacter to use the Japanese Era code point,U+32FF, from the Unicode Standard version 12.1. Consequently, the behavior of fields and methods of classCharacter may vary across implementations of the Java SE 11 Platform when processing the aforementioned code point ( outside of version 10.0 ), except for the following methods that define Java identifiers:isJavaIdentifierStart(int),isJavaIdentifierStart(char),isJavaIdentifierPart(int), andisJavaIdentifierPart(char). Code points in Java identifiers must be drawn from version 10.0 of the Unicode Standard.

    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.

    Since:
    1.0
    See Also:
    Serialized Form
    • Constructor Summary

      Constructors 
      ConstructorDescription
      Character​(char value)
      Deprecated.
      It is rarely appropriate to use this constructor.
    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods 
      Modifier and TypeMethodDescription
      static intcharCount​(int codePoint)
      Determines the number ofchar values needed to represent the specified character (Unicode code point).
      charcharValue()
      Returns the value of thisCharacter object.
      static intcodePointAt​(char[] a, int index)
      Returns the code point at the given index of thechar array.
      static intcodePointAt​(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 intcodePointAt​(CharSequence seq, int index)
      Returns the code point at the given index of theCharSequence.
      static intcodePointBefore​(char[] a, int index)
      Returns the code point preceding the given index of thechar array.
      static intcodePointBefore​(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 intcodePointBefore​(CharSequence seq, int index)
      Returns the code point preceding the given index of theCharSequence.
      static intcodePointCount​(char[] a, int offset, int count)
      Returns the number of Unicode code points in a subarray of thechar array argument.
      static intcodePointCount​(CharSequence seq, int beginIndex, int endIndex)
      Returns the number of Unicode code points in the text range of the specified char sequence.
      static intcodePointOf​(String name)
      Returns the code point value of the Unicode character specified by the given Unicode character name.
      static intcompare​(char x, char y)
      Compares twochar values numerically.
      intcompareTo​(Character anotherCharacter)
      Compares twoCharacter objects numerically.
      static intdigit​(char ch, int radix)
      Returns the numeric value of the characterch in the specified radix.
      static intdigit​(int codePoint, int radix)
      Returns the numeric value of the specified character (Unicode code point) in the specified radix.
      booleanequals​(Object obj)
      Compares this object against the specified object.
      static charforDigit​(int digit, int radix)
      Determines the character representation for a specific digit in the specified radix.
      static bytegetDirectionality​(char ch)
      Returns the Unicode directionality property for the given character.
      static bytegetDirectionality​(int codePoint)
      Returns the Unicode directionality property for the given character (Unicode code point).
      staticStringgetName​(int codePoint)
      Returns the Unicode name of the specified charactercodePoint, or null if the code point isunassigned.
      static intgetNumericValue​(char ch)
      Returns theint value that the specified Unicode character represents.
      static intgetNumericValue​(int codePoint)
      Returns theint value that the specified character (Unicode code point) represents.
      static intgetType​(char ch)
      Returns a value indicating a character's general category.
      static intgetType​(int codePoint)
      Returns a value indicating a character's general category.
      inthashCode()
      Returns a hash code for thisCharacter; equal to the result of invokingcharValue().
      static inthashCode​(char value)
      Returns a hash code for achar value; compatible withCharacter.hashCode().
      static charhighSurrogate​(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 booleanisAlphabetic​(int codePoint)
      Determines if the specified character (Unicode code point) is an alphabet.
      static booleanisBmpCodePoint​(int codePoint)
      Determines whether the specified character (Unicode code point) is in theBasic Multilingual Plane (BMP).
      static booleanisDefined​(char ch)
      Determines if a character is defined in Unicode.
      static booleanisDefined​(int codePoint)
      Determines if a character (Unicode code point) is defined in Unicode.
      static booleanisDigit​(char ch)
      Determines if the specified character is a digit.
      static booleanisDigit​(int codePoint)
      Determines if the specified character (Unicode code point) is a digit.
      static booleanisHighSurrogate​(char ch)
      Determines if the givenchar value is a Unicode high-surrogate code unit (also known asleading-surrogate code unit).
      static booleanisIdentifierIgnorable​(char ch)
      Determines if the specified character should be regarded as an ignorable character in a Java identifier or a Unicode identifier.
      static booleanisIdentifierIgnorable​(int codePoint)
      Determines if the specified character (Unicode code point) should be regarded as an ignorable character in a Java identifier or a Unicode identifier.
      static booleanisIdeographic​(int codePoint)
      Determines if the specified character (Unicode code point) is a CJKV (Chinese, Japanese, Korean and Vietnamese) ideograph, as defined by the Unicode Standard.
      static booleanisISOControl​(char ch)
      Determines if the specified character is an ISO control character.
      static booleanisISOControl​(int codePoint)
      Determines if the referenced character (Unicode code point) is an ISO control character.
      static booleanisJavaIdentifierPart​(char ch)
      Determines if the specified character may be part of a Java identifier as other than the first character.
      static booleanisJavaIdentifierPart​(int codePoint)
      Determines if the character (Unicode code point) may be part of a Java identifier as other than the first character.
      static booleanisJavaIdentifierStart​(char ch)
      Determines if the specified character is permissible as the first character in a Java identifier.
      static booleanisJavaIdentifierStart​(int codePoint)
      Determines if the character (Unicode code point) is permissible as the first character in a Java identifier.
      static booleanisJavaLetter​(char ch)
      Deprecated.
      Replaced by isJavaIdentifierStart(char).
      static booleanisJavaLetterOrDigit​(char ch)
      Deprecated.
      Replaced by isJavaIdentifierPart(char).
      static booleanisLetter​(char ch)
      Determines if the specified character is a letter.
      static booleanisLetter​(int codePoint)
      Determines if the specified character (Unicode code point) is a letter.
      static booleanisLetterOrDigit​(char ch)
      Determines if the specified character is a letter or digit.
      static booleanisLetterOrDigit​(int codePoint)
      Determines if the specified character (Unicode code point) is a letter or digit.
      static booleanisLowerCase​(char ch)
      Determines if the specified character is a lowercase character.
      static booleanisLowerCase​(int codePoint)
      Determines if the specified character (Unicode code point) is a lowercase character.
      static booleanisLowSurrogate​(char ch)
      Determines if the givenchar value is a Unicode low-surrogate code unit (also known astrailing-surrogate code unit).
      static booleanisMirrored​(char ch)
      Determines whether the character is mirrored according to the Unicode specification.
      static booleanisMirrored​(int codePoint)
      Determines whether the specified character (Unicode code point) is mirrored according to the Unicode specification.
      static booleanisSpace​(char ch)
      Deprecated.
      Replaced by isWhitespace(char).
      static booleanisSpaceChar​(char ch)
      Determines if the specified character is a Unicode space character.
      static booleanisSpaceChar​(int codePoint)
      Determines if the specified character (Unicode code point) is a Unicode space character.
      static booleanisSupplementaryCodePoint​(int codePoint)
      Determines whether the specified character (Unicode code point) is in thesupplementary character range.
      static booleanisSurrogate​(char ch)
      Determines if the givenchar value is a Unicodesurrogate code unit.
      static booleanisSurrogatePair​(char high, char low)
      Determines whether the specified pair ofchar values is a valid Unicode surrogate pair.
      static booleanisTitleCase​(char ch)
      Determines if the specified character is a titlecase character.
      static booleanisTitleCase​(int codePoint)
      Determines if the specified character (Unicode code point) is a titlecase character.
      static booleanisUnicodeIdentifierPart​(char ch)
      Determines if the specified character may be part of a Unicode identifier as other than the first character.
      static booleanisUnicodeIdentifierPart​(int codePoint)
      Determines if the specified character (Unicode code point) may be part of a Unicode identifier as other than the first character.
      static booleanisUnicodeIdentifierStart​(char ch)
      Determines if the specified character is permissible as the first character in a Unicode identifier.
      static booleanisUnicodeIdentifierStart​(int codePoint)
      Determines if the specified character (Unicode code point) is permissible as the first character in a Unicode identifier.
      static booleanisUpperCase​(char ch)
      Determines if the specified character is an uppercase character.
      static booleanisUpperCase​(int codePoint)
      Determines if the specified character (Unicode code point) is an uppercase character.
      static booleanisValidCodePoint​(int codePoint)
      Determines whether the specified code point is a valid Unicode code point value.
      static booleanisWhitespace​(char ch)
      Determines if the specified character is white space according to Java.
      static booleanisWhitespace​(int codePoint)
      Determines if the specified character (Unicode code point) is white space according to Java.
      static charlowSurrogate​(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 intoffsetByCodePoints​(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 intoffsetByCodePoints​(CharSequence seq, int index, int codePointOffset)
      Returns the index within the given char sequence that is offset from the givenindex bycodePointOffset code points.
      static charreverseBytes​(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 inttoChars​(int codePoint, char[] dst, int dstIndex)
      Converts the specified character (Unicode code point) to its UTF-16 representation.
      static inttoCodePoint​(char high, char low)
      Converts the specified surrogate pair to its supplementary code point value.
      static chartoLowerCase​(char ch)
      Converts the character argument to lowercase using case mapping information from the UnicodeData file.
      static inttoLowerCase​(int codePoint)
      Converts the character (Unicode code point) argument to lowercase using case mapping information from the UnicodeData file.
      StringtoString()
      Returns aString object representing thisCharacter's value.
      staticStringtoString​(char c)
      Returns aString object representing the specifiedchar.
      staticStringtoString​(int codePoint)
      Returns aString object representing the specified character (Unicode code point).
      static chartoTitleCase​(char ch)
      Converts the character argument to titlecase using case mapping information from the UnicodeData file.
      static inttoTitleCase​(int codePoint)
      Converts the character (Unicode code point) argument to titlecase using case mapping information from the UnicodeData file.
      static chartoUpperCase​(char ch)
      Converts the character argument to uppercase using case mapping information from the UnicodeData file.
      static inttoUpperCase​(int codePoint)
      Converts the character (Unicode code point) argument to uppercase using case mapping information from the UnicodeData file.
      staticCharactervalueOf​(char c)
      Returns aCharacter instance representing the specifiedchar value.
    • Field Detail

      • 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:
        Constant Field Values
      • 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:
        Constant Field Values
      • 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:
        Constant Field Values
      • UPPERCASE_LETTER

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        public static final byte DIRECTIONALITY_OTHER_NEUTRALS
        Neutral bidirectional character type "ON" in the Unicode specification.
        Since:
        1.4
        See Also:
        Constant Field Values
      • 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:
        Constant Field Values
      • 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:
        Constant Field Values
      • 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:
        Constant Field Values
      • 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:
        Constant Field Values
      • 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:
        Constant Field Values
      • 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:
        Constant Field Values
      • 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:
        Constant Field Values
      • 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:
        Constant Field Values
      • 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:
        Constant Field Values
      • 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:
        Constant Field Values
      • 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:
        Constant Field Values
      • 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:
        Constant Field Values
      • BYTES

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

      • Character

        @Deprecated(since="9")public Character​(char value)
        Deprecated.
        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 Detail

      • 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 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:
        Object.hashCode(),HashMap
      • 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
      • 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:
        isSupplementaryCodePoint(int)
      • 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 then 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(char),isTitleCase(char),toLowerCase(char),getType(char)
      • 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:
        isLowerCase(int),isTitleCase(int),toLowerCase(int),getType(int)
      • 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:
        isLowerCase(char),isTitleCase(char),toUpperCase(char),getType(char)
      • 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:
        isLowerCase(int),isTitleCase(int),toUpperCase(int),getType(int)
      • 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:
        isLowerCase(char),isUpperCase(char),toTitleCase(char),getType(char)
      • 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:
        isLowerCase(int),isUpperCase(int),toTitleCase(int),getType(int)
      • 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:
        digit(char, int),forDigit(int, int),getType(char)
      • 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:
        forDigit(int, int),getType(int)
      • 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:
        isDigit(int),isLetter(int),isLetterOrDigit(int),isLowerCase(int),isTitleCase(int),isUpperCase(int)
      • 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.
        These conditions are tested against the character information from version 10.0 of the Unicode Standard.

        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:
        isJavaLetter(char),isJavaIdentifierStart(char),isJavaIdentifierPart(char),isLetter(char),isLetterOrDigit(char),isUnicodeIdentifierPart(char),isIdentifierIgnorable(char)
      • isAlphabetic

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

        A character is considered to be alphabetic if its general category type, provided 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'_').
        These conditions are tested against the character information from version 10.0 of the Unicode Standard.

        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:
        isJavaIdentifierPart(char),isLetter(char),isUnicodeIdentifierStart(char),SourceVersion.isIdentifier(CharSequence)
      • 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'_').
        These conditions are tested against the character information from version 10.0 of the Unicode Standard.

        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(int),isLetter(int),isUnicodeIdentifierStart(int),SourceVersion.isIdentifier(CharSequence)
      • 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
        These conditions are tested against the character information from version 10.0 of the Unicode Standard.

        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:
        isIdentifierIgnorable(char),isJavaIdentifierStart(char),isLetterOrDigit(char),isUnicodeIdentifierPart(char),SourceVersion.isIdentifier(CharSequence)
      • 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
        These conditions are tested against the character information from version 10.0 of the Unicode Standard.

        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:
        isIdentifierIgnorable(int),isJavaIdentifierStart(int),isLetterOrDigit(int),isUnicodeIdentifierPart(int),SourceVersion.isIdentifier(CharSequence)
      • 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:

        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
        See Also:
        isJavaIdentifierStart(int),isLetter(int),isUnicodeIdentifierPart(int)
      • 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.

        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
        See Also:
        isIdentifierIgnorable(char),isJavaIdentifierPart(char),isLetterOrDigit(char),isUnicodeIdentifierStart(char)
      • 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.

        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
        See Also:
        isIdentifierIgnorable(int),isJavaIdentifierPart(int),isLetterOrDigit(int),isUnicodeIdentifierStart(int)
      • 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:
        isJavaIdentifierPart(char),isUnicodeIdentifierPart(char)
      • 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:
        isJavaIdentifierPart(int),isUnicodeIdentifierPart(int)
      • 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:
        isLowerCase(char),String.toLowerCase()
      • 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:
        isLowerCase(int),String.toLowerCase()
      • 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:
        isUpperCase(char),String.toUpperCase()
      • 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:
        isUpperCase(int),String.toUpperCase()
      • 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:
        isTitleCase(char),toLowerCase(char),toUpperCase(char)
      • 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:
        isTitleCase(int),toLowerCase(int),toUpperCase(int)
      • 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:
        forDigit(int, int),isDigit(char)
      • 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:
        forDigit(int, int),isDigit(int)
      • 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:
        forDigit(int, int),isDigit(char)
      • 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:
        forDigit(int, int),isDigit(int)
      • 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(char),isWhitespace(char)
      • 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:
        isWhitespace(char)
      • 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(int)
      • 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:
        isSpaceChar(char)
      • 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:
        isSpaceChar(int)
      • 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:
        isSpaceChar(char),isWhitespace(char)
      • 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:
        isSpaceChar(int),isWhitespace(int)
      • 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:
        MIN_RADIX,MAX_RADIX,digit(char, int)
      • 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 Unicode name of the specified charactercodePoint, or null if the code point isunassigned.

        Note: 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 expression.

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

        Parameters:
        codePoint - the character (Unicode code point)
        Returns:
        the Unicode name of the specified character, or null if the code point is unassigned.
        Throws:
        IllegalArgumentException - if the 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 Unicode character name.

        Note: 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 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.

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