Class UCharacter

java.lang.Object
com.ibm.icu.lang.UCharacter
All Implemented Interfaces:
UCharacterEnums.ECharacterCategory, UCharacterEnums.ECharacterDirection

public final class UCharacter extends Object implements UCharacterEnums.ECharacterCategory, UCharacterEnums.ECharacterDirection
.

The UCharacter class provides extensions to the Character class. These extensions provide support for more Unicode properties. Each ICU release supports the latest version of Unicode available at that time.

For some time before Java 5 added support for supplementary Unicode code points, The ICU UCharacter class and many other ICU classes already supported them. Some UCharacter methods and constants were widened slightly differently than how the Character class methods and constants were widened later. In particular, Character.MAX_VALUE is still a char with the value U+FFFF, while the MAX_VALUE is an int with the value U+10FFFF.

Code points are represented in these API using ints. While it would be more convenient in Java to have a separate primitive datatype for them, ints suffice in the meantime.

To use this class please add the jar file name icu4j.jar to the class path, since it contains data files which supply the information used by this file.
E.g. In Windows
set CLASSPATH=%CLASSPATH%;$JAR_FILE_PATH/ucharacter.jar.
Otherwise, another method would be to copy the files uprops.dat and unames.icu from the icu4j source subdirectory $ICU4J_SRC/src/com.ibm.icu.impl.data to your class directory $ICU4J_CLASS/com.ibm.icu.impl.data.

Aside from the additions for UTF-16 support, and the updated Unicode properties, the main differences between UCharacter and Character are:

  • UCharacter is not designed to be a char wrapper and does not have APIs to which involves management of that single char.
    These include:
    • char charValue(),
    • int compareTo(java.lang.Character, java.lang.Character), etc.
  • UCharacter does not include Character APIs that are deprecated, nor does it include the Java-specific character information, such as boolean isJavaIdentifierPart(char ch).
  • Character maps characters 'A' - 'Z' and 'a' - 'z' to the numeric values '10' - '35'. UCharacter also does this in digit and getNumericValue, to adhere to the java semantics of these methods. New methods unicodeDigit, and getUnicodeNumericValue do not treat the above code points as having numeric values. This is a semantic change from ICU4J 1.3.1.

Further detail on differences can be determined using the program com.ibm.icu.dev.test.lang.UCharacterCompare

In addition to Java compatibility functions, which calculate derived properties, this API provides low-level access to the Unicode Character Database.

Unicode assigns each code point (not just assigned character) values for many properties. Most of them are simple boolean flags, or constants from a small enumerated list. For some properties, values are strings or other relatively more complex types.

For more information see "About the Unicode Character Database" (http://www.unicode.org/ucd/) and the ICU User Guide chapter on Properties (https://unicode-org.github.io/icu/userguide/strings/properties).

There are also functions that provide easy migration from C/POSIX functions like isblank(). Their use is generally discouraged because the C/POSIX standards do not define their semantics beyond the ASCII range, which means that different implementations exhibit very different behavior. Instead, Unicode properties should be used directly.

There are also only a few, broad C/POSIX character classes, and they tend to be used for conflicting purposes. For example, the "isalpha()" class is sometimes used to determine word boundaries, while a more sophisticated approach would at least distinguish initial letters from continuation characters (the latter including combining marks). (In ICU, BreakIterator is the most sophisticated API for word boundaries.) Another example: There is no "istitle()" class for titlecase characters.

ICU 3.4 and later provides API access for all twelve C/POSIX character classes. ICU implements them according to the Standard Recommendations in Annex C: Compatibility Properties of UTS #18 Unicode Regular Expressions (http://www.unicode.org/reports/tr18/#Compatibility_Properties).

API access for C/POSIX character classes is as follows:


 - alpha:     isUAlphabetic(c) or hasBinaryProperty(c, UProperty.ALPHABETIC)
 - lower:     isULowercase(c) or hasBinaryProperty(c, UProperty.LOWERCASE)
 - upper:     isUUppercase(c) or hasBinaryProperty(c, UProperty.UPPERCASE)
 - punct:     ((1<<getType(c)) & ((1<<DASH_PUNCTUATION)|(1<<START_PUNCTUATION)|
               (1<<END_PUNCTUATION)|(1<<CONNECTOR_PUNCTUATION)|(1<<OTHER_PUNCTUATION)|
               (1<<INITIAL_PUNCTUATION)|(1<<FINAL_PUNCTUATION)))!=0
 - digit:     isDigit(c) or getType(c)==DECIMAL_DIGIT_NUMBER
 - xdigit:    hasBinaryProperty(c, UProperty.POSIX_XDIGIT)
 - alnum:     hasBinaryProperty(c, UProperty.POSIX_ALNUM)
 - space:     isUWhiteSpace(c) or hasBinaryProperty(c, UProperty.WHITE_SPACE)
 - blank:     hasBinaryProperty(c, UProperty.POSIX_BLANK)
 - cntrl:     getType(c)==CONTROL
 - graph:     hasBinaryProperty(c, UProperty.POSIX_GRAPH)
 - print:     hasBinaryProperty(c, UProperty.POSIX_PRINT)

The C/POSIX character classes are also available in UnicodeSet patterns, using patterns like [:graph:] or \p{graph}.

There are several ICU (and Java) whitespace functions. Comparison:

  • isUWhiteSpace=UCHAR_WHITE_SPACE: Unicode White_Space property; most of general categories "Z" (separators) + most whitespace ISO controls (including no-break spaces, but excluding IS1..IS4)
  • isWhitespace: Java isWhitespace; Z + whitespace ISO controls but excluding no-break spaces
  • isSpaceChar: just Z (including no-break spaces)

This class is not subclassable.

Author:
Syn Wee Quek
See Also:
  • Field Details

    • MIN_VALUE

      public static final int MIN_VALUE
      The lowest Unicode code point value, constant 0. Same as Character.MIN_CODE_POINT, same integer value as Character.MIN_VALUE.
      See Also:
    • MAX_VALUE

      public static final int MAX_VALUE
      The highest Unicode code point value (scalar value), constant U+10FFFF (uses 21 bits). Same as Character.MAX_CODE_POINT.

      Up-to-date Unicode implementation of Character.MAX_VALUE which is still a char with the value U+FFFF.

      See Also:
    • SUPPLEMENTARY_MIN_VALUE

      public static final int SUPPLEMENTARY_MIN_VALUE
      The minimum value for Supplementary code points, constant U+10000. Same as Character.MIN_SUPPLEMENTARY_CODE_POINT.
      See Also:
    • REPLACEMENT_CHAR

      public static final int REPLACEMENT_CHAR
      Unicode value used when translating into Unicode encoding form and there is no existing character.
      See Also:
    • NO_NUMERIC_VALUE

      public static final double NO_NUMERIC_VALUE
      Special value that is returned by getUnicodeNumericValue(int) when no numeric value is defined for a code point.
      See Also:
    • MIN_RADIX

      public static final int MIN_RADIX
      Compatibility constant for Java Character's MIN_RADIX.
      See Also:
    • MAX_RADIX

      public static final int MAX_RADIX
      Compatibility constant for Java Character's MAX_RADIX.
      See Also:
    • TITLECASE_NO_LOWERCASE

      public static final int TITLECASE_NO_LOWERCASE
      Do not lowercase non-initial parts of words when titlecasing. Option bit for titlecasing APIs that take an options bit set. By default, titlecasing will titlecase the first cased character of a word and lowercase all other characters. With this option, the other characters will not be modified.
      See Also:
    • TITLECASE_NO_BREAK_ADJUSTMENT

      public static final int TITLECASE_NO_BREAK_ADJUSTMENT
      Do not adjust the titlecasing indexes from BreakIterator::next() indexes; titlecase exactly the characters at breaks from the iterator. Option bit for titlecasing APIs that take an options bit set. By default, titlecasing will take each break iterator index, adjust it by looking for the next cased character, and titlecase that one. Other characters are lowercased. This follows Unicode 4 & 5 section 3.13 Default Case Operations: R3 toTitlecase(X): Find the word boundaries based on Unicode Standard Annex #29, "Text Boundaries." Between each pair of word boundaries, find the first cased character F. If F exists, map F to default_title(F); then map each subsequent character C to default_lower(C).
      See Also:
    • FOLD_CASE_DEFAULT

      public static final int FOLD_CASE_DEFAULT
      Option value for case folding: use default mappings defined in CaseFolding.txt.
      See Also:
    • FOLD_CASE_EXCLUDE_SPECIAL_I

      public static final int FOLD_CASE_EXCLUDE_SPECIAL_I
      Option value for case folding: Use the modified set of mappings provided in CaseFolding.txt to handle dotted I and dotless i appropriately for Turkic languages (tr, az).

      Before Unicode 3.2, CaseFolding.txt contains mappings marked with 'I' that are to be included for default mappings and excluded for the Turkic-specific mappings.

      Unicode 3.2 CaseFolding.txt instead contains mappings marked with 'T' that are to be excluded for default mappings and included for the Turkic-specific mappings.

      See Also:
    • MIN_HIGH_SURROGATE

      public static final char MIN_HIGH_SURROGATE
      Constant U+D800, same as Character.MIN_HIGH_SURROGATE.
      See Also:
    • MAX_HIGH_SURROGATE

      public static final char MAX_HIGH_SURROGATE
      Constant U+DBFF, same as Character.MAX_HIGH_SURROGATE.
      See Also:
    • MIN_LOW_SURROGATE

      public static final char MIN_LOW_SURROGATE
      Constant U+DC00, same as Character.MIN_LOW_SURROGATE.
      See Also:
    • MAX_LOW_SURROGATE

      public static final char MAX_LOW_SURROGATE
      Constant U+DFFF, same as Character.MAX_LOW_SURROGATE.
      See Also:
    • MIN_SURROGATE

      public static final char MIN_SURROGATE
      Constant U+D800, same as Character.MIN_SURROGATE.
      See Also:
    • MAX_SURROGATE

      public static final char MAX_SURROGATE
      Constant U+DFFF, same as Character.MAX_SURROGATE.
      See Also:
    • MIN_SUPPLEMENTARY_CODE_POINT

      public static final int MIN_SUPPLEMENTARY_CODE_POINT
      Constant U+10000, same as Character.MIN_SUPPLEMENTARY_CODE_POINT.
      See Also:
    • MAX_CODE_POINT

      public static final int MAX_CODE_POINT
      Constant U+10FFFF, same as Character.MAX_CODE_POINT.
      See Also:
    • MIN_CODE_POINT

      public static final int MIN_CODE_POINT
      Constant U+0000, same as Character.MIN_CODE_POINT.
      See Also:
  • Method Details

    • digit

      public static int digit(int ch, int radix)
      Returnss the numeric value of a decimal digit code point.
      This method observes the semantics of java.lang.Character.digit(). Note that this will return positive values for code points for which isDigit returns false, just like java.lang.Character.
      Semantic Change: In release 1.3.1 and prior, this did not treat the European letters as having a digit value, and also treated numeric letters and other numbers as digits. This has been changed to conform to the java semantics.
      A code point is a valid digit if and only if:
      • ch is a decimal digit or one of the european letters, and
      • the value of ch is less than the specified radix.
      Parameters:
      ch - the code point to query
      radix - the radix
      Returns:
      the numeric value represented by the code point in the specified radix, or -1 if the code point is not a decimal digit or if its value is too large for the radix
    • digit

      public static int digit(int ch)
      Returnss the numeric value of a decimal digit code point.
      This is a convenience overload of digit(int, int) that provides a decimal radix.
      Semantic Change: In release 1.3.1 and prior, this treated numeric letters and other numbers as digits. This has been changed to conform to the java semantics.
      Parameters:
      ch - the code point to query
      Returns:
      the numeric value represented by the code point, or -1 if the code point is not a decimal digit or if its value is too large for a decimal radix
    • getNumericValue

      public static int getNumericValue(int ch)
      Returns the numeric value of the code point as a nonnegative integer.
      If the code point does not have a numeric value, then -1 is returned.
      If the code point has a numeric value that cannot be represented as a nonnegative integer (for example, a fractional value), then -2 is returned.
      Parameters:
      ch - the code point to query
      Returns:
      the numeric value of the code point, or -1 if it has no numeric value, or -2 if it has a numeric value that cannot be represented as a nonnegative integer
    • getUnicodeNumericValue

      public static double getUnicodeNumericValue(int ch)
      Returns the numeric value for a Unicode code point as defined in the Unicode Character Database.

      A "double" return type is necessary because some numeric values are fractions, negative, or too large for int.

      For characters without any numeric values in the Unicode Character Database, this function will return NO_NUMERIC_VALUE. Note: This is different from the Unicode Standard which specifies NaN as the default value.

      API Change: In release 2.2 and prior, this API has a return type int and returns -1 when the argument ch does not have a corresponding numeric value. This has been changed to synch with ICU4C This corresponds to the ICU4C function u_getNumericValue.

      Parameters:
      ch - Code point to get the numeric value for.
      Returns:
      numeric value of ch, or NO_NUMERIC_VALUE if none is defined.
    • isSpace

      @Deprecated public static boolean isSpace(int ch)
      Deprecated.
      ICU 3.4 (Java)
      Compatibility override of Java deprecated method. This method will always remain deprecated. Same as java.lang.Character.isSpace().
      Parameters:
      ch - the code point
      Returns:
      true if the code point is a space character as defined by java.lang.Character.isSpace.
    • getType

      public static int getType(int ch)
      Returns a value indicating a code point's Unicode category. Up-to-date Unicode implementation of java.lang.Character.getType() except for the above mentioned code points that had their category changed.
      Return results are constants from the interface UCharacterCategory
      NOTE: the UCharacterCategory values are not compatible with those returned by java.lang.Character.getType. UCharacterCategory values match the ones used in ICU4C, while java.lang.Character type values, though similar, skip the value 17.
      Parameters:
      ch - code point whose type is to be determined
      Returns:
      category which is a value of UCharacterCategory
    • isDefined

      public static boolean isDefined(int ch)
      Determines if a code point has a defined meaning in the up-to-date Unicode standard. E.g. supplementary code points though allocated space are not defined in Unicode yet.
      Up-to-date Unicode implementation of java.lang.Character.isDefined()
      Parameters:
      ch - code point to be determined if it is defined in the most current version of Unicode
      Returns:
      true if this code point is defined in unicode
    • isDigit

      public static boolean isDigit(int ch)
      Determines if a code point is a Java digit.
      This method observes the semantics of java.lang.Character.isDigit(). It returns true for decimal digits only.
      Semantic Change: In release 1.3.1 and prior, this treated numeric letters and other numbers as digits. This has been changed to conform to the java semantics.
      Parameters:
      ch - code point to query
      Returns:
      true if this code point is a digit
    • isISOControl

      public static boolean isISOControl(int ch)
      Determines if the specified code point is an ISO control character. A code point is considered to be an ISO control character if it is in the range \u0000 through \u001F or in the range \u007F through \u009F.
      Up-to-date Unicode implementation of java.lang.Character.isISOControl()
      Parameters:
      ch - code point to determine if it is an ISO control character
      Returns:
      true if code point is a ISO control character
    • isLetter

      public static boolean isLetter(int ch)
      Determines if the specified code point is a letter. Up-to-date Unicode implementation of java.lang.Character.isLetter()
      Parameters:
      ch - code point to determine if it is a letter
      Returns:
      true if code point is a letter
    • isLetterOrDigit

      public static boolean isLetterOrDigit(int ch)
      Determines if the specified code point is a letter or digit. This method, unlike java.lang.Character does not regard the ascii characters 'A' - 'Z' and 'a' - 'z' as digits.
      Parameters:
      ch - code point to determine if it is a letter or a digit
      Returns:
      true if code point is a letter or a digit
    • isJavaLetter

      @Deprecated public static boolean isJavaLetter(int cp)
      Deprecated.
      ICU 3.4 (Java)
      Compatibility override of Java deprecated method. This method will always remain deprecated. Delegates to java.lang.Character.isJavaIdentifierStart.
      Parameters:
      cp - the code point
      Returns:
      true if the code point can start a java identifier.
    • isJavaLetterOrDigit

      @Deprecated public static boolean isJavaLetterOrDigit(int cp)
      Deprecated.
      ICU 3.4 (Java)
      Compatibility override of Java deprecated method. This method will always remain deprecated. Delegates to java.lang.Character.isJavaIdentifierPart.
      Parameters:
      cp - the code point
      Returns:
      true if the code point can continue a java identifier.
    • isJavaIdentifierStart

      public static boolean isJavaIdentifierStart(int cp)
      Compatibility override of Java method, delegates to java.lang.Character.isJavaIdentifierStart.
      Parameters:
      cp - the code point
      Returns:
      true if the code point can start a java identifier.
    • isJavaIdentifierPart

      public static boolean isJavaIdentifierPart(int cp)
      Compatibility override of Java method, delegates to java.lang.Character.isJavaIdentifierPart.
      Parameters:
      cp - the code point
      Returns:
      true if the code point can continue a java identifier.
    • isLowerCase

      public static boolean isLowerCase(int ch)
      Determines if the specified code point is a lowercase character. UnicodeData only contains case mappings for code points where they are one-to-one mappings; it also omits information about context-sensitive case mappings.
      For more information about Unicode case mapping please refer to the Technical report #21.
      Up-to-date Unicode implementation of java.lang.Character.isLowerCase()
      Parameters:
      ch - code point to determine if it is in lowercase
      Returns:
      true if code point is a lowercase character
    • isWhitespace

      public static boolean isWhitespace(int ch)
      Determines if the specified code point is a white space character. A code point is considered to be an whitespace character if and only if it satisfies one of the following criteria:
      • It is a Unicode Separator character (categories "Z" = "Zs" or "Zl" or "Zp"), but is not also a non-breaking space (\u00A0 or \u2007 or \u202F).
      • It is \u0009, HORIZONTAL TABULATION.
      • It is \u000A, LINE FEED.
      • It is \u000B, VERTICAL TABULATION.
      • It is \u000C, FORM FEED.
      • It is \u000D, CARRIAGE RETURN.
      • It is \u001C, FILE SEPARATOR.
      • It is \u001D, GROUP SEPARATOR.
      • It is \u001E, RECORD SEPARATOR.
      • It is \u001F, UNIT SEPARATOR.
      This API tries to sync with the semantics of Java's java.lang.Character.isWhitespace(), but it may not return the exact same results because of the Unicode version difference.

      Note: Unicode 4.0.1 changed U+200B ZERO WIDTH SPACE from a Space Separator (Zs) to a Format Control (Cf). Since then, isWhitespace(0x200b) returns false. See http://www.unicode.org/versions/Unicode4.0.1/

      Parameters:
      ch - code point to determine if it is a white space
      Returns:
      true if the specified code point is a white space character
    • isSpaceChar

      public static boolean isSpaceChar(int ch)
      Determines if the specified code point is a Unicode specified space character, i.e. if code point is in the category Zs, Zl and Zp. Up-to-date Unicode implementation of java.lang.Character.isSpaceChar().
      Parameters:
      ch - code point to determine if it is a space
      Returns:
      true if the specified code point is a space character
    • isTitleCase

      public static boolean isTitleCase(int ch)
      Determines if the specified code point is a titlecase character. UnicodeData only contains case mappings for code points where they are one-to-one mappings; it also omits information about context-sensitive case mappings.
      For more information about Unicode case mapping please refer to the Technical report #21.
      Up-to-date Unicode implementation of java.lang.Character.isTitleCase().
      Parameters:
      ch - code point to determine if it is in title case
      Returns:
      true if the specified code point is a titlecase character
    • isUnicodeIdentifierPart

      public static boolean isUnicodeIdentifierPart(int ch)
      Determines if the specified character is permissible as a non-initial character of an identifier according to UAX #31 Unicode Identifier and Pattern Syntax.

      Same as Unicode ID_Continue (UProperty.ID_CONTINUE).

      Note that this differs from Character.isUnicodeIdentifierPart(char) which implements a different identifier profile.

      Parameters:
      ch - the code point to be tested
      Returns:
      true if the code point may occur as a non-initial character of an identifier
    • isUnicodeIdentifierStart

      public static boolean isUnicodeIdentifierStart(int ch)
      Determines if the specified character is permissible as the first character in an identifier according to UAX #31 Unicode Identifier and Pattern Syntax.

      Same as Unicode ID_Start (UProperty.ID_START).

      Note that this differs from Character.isUnicodeIdentifierStart(char) which implements a different identifier profile.

      Parameters:
      ch - the code point to be tested
      Returns:
      true if the code point may start an identifier
    • isIdentifierIgnorable

      public static boolean isIdentifierIgnorable(int ch)
      Determines if the specified code point should be regarded as an ignorable character in a Java identifier. A character is Java-identifier-ignorable if it has the general category Cf Formatting Control, or it is a non-Java-whitespace ISO control: U+0000..U+0008, U+000E..U+001B, U+007F..U+009F.
      Up-to-date Unicode implementation of java.lang.Character.isIdentifierIgnorable().
      See UTR #8.

      Note that Unicode just recommends to ignore Cf (format controls).

      Parameters:
      ch - code point to be determined if it can be ignored in a Unicode identifier.
      Returns:
      true if the code point is ignorable
    • isUpperCase

      public static boolean isUpperCase(int ch)
      Determines if the specified code point is an uppercase character. UnicodeData only contains case mappings for code point where they are one-to-one mappings; it also omits information about context-sensitive case mappings.
      For language specific case conversion behavior, use toUpperCase(locale, str).
      For example, the case conversion for dot-less i and dotted I in Turkish, or for final sigma in Greek. For more information about Unicode case mapping please refer to the Technical report #21.
      Up-to-date Unicode implementation of java.lang.Character.isUpperCase().
      Parameters:
      ch - code point to determine if it is in uppercase
      Returns:
      true if the code point is an uppercase character
    • toLowerCase

      public static int toLowerCase(int ch)
      The given code point is mapped to its lowercase equivalent; if the code point has no lowercase equivalent, the code point itself is returned. Up-to-date Unicode implementation of java.lang.Character.toLowerCase()

      This function only returns the simple, single-code point case mapping. Full case mappings should be used whenever possible because they produce better results by working on whole strings. They take into account the string context and the language and can map to a result string with a different length as appropriate. Full case mappings are applied by the case mapping functions that take String parameters rather than code points (int). See also the User Guide chapter on C/POSIX migration: https://unicode-org.github.io/icu/userguide/icu/posix#case-mappings

      Parameters:
      ch - code point whose lowercase equivalent is to be retrieved
      Returns:
      the lowercase equivalent code point
    • toString

      public static String toString(int ch)
      Converts argument code point and returns a String object representing the code point's value in UTF-16 format. The result is a string whose length is 1 for BMP code points, 2 for supplementary ones.

      Up-to-date Unicode implementation of java.lang.Character.toString().

      Parameters:
      ch - code point
      Returns:
      string representation of the code point, null if code point is not defined in unicode
    • toTitleCase

      public static int toTitleCase(int ch)
      Converts the code point argument to titlecase. If no titlecase is available, the uppercase is returned. If no uppercase is available, the code point itself is returned. Up-to-date Unicode implementation of java.lang.Character.toTitleCase()

      This function only returns the simple, single-code point case mapping. Full case mappings should be used whenever possible because they produce better results by working on whole strings. They take into account the string context and the language and can map to a result string with a different length as appropriate. Full case mappings are applied by the case mapping functions that take String parameters rather than code points (int). See also the User Guide chapter on C/POSIX migration: https://unicode-org.github.io/icu/userguide/icu/posix#case-mappings

      Parameters:
      ch - code point whose title case is to be retrieved
      Returns:
      titlecase code point
    • toUpperCase

      public static int toUpperCase(int ch)
      Converts the character argument to uppercase. If no uppercase is available, the character itself is returned. Up-to-date Unicode implementation of java.lang.Character.toUpperCase()

      This function only returns the simple, single-code point case mapping. Full case mappings should be used whenever possible because they produce better results by working on whole strings. They take into account the string context and the language and can map to a result string with a different length as appropriate. Full case mappings are applied by the case mapping functions that take String parameters rather than code points (int). See also the User Guide chapter on C/POSIX migration: https://unicode-org.github.io/icu/userguide/icu/posix#case-mappings

      Parameters:
      ch - code point whose uppercase is to be retrieved
      Returns:
      uppercase code point
    • isSupplementary

      public static boolean isSupplementary(int ch)
      Determines if the code point is a supplementary character. A code point is a supplementary character if and only if it is greater than SUPPLEMENTARY_MIN_VALUE
      Parameters:
      ch - code point to be determined if it is in the supplementary plane
      Returns:
      true if code point is a supplementary character
    • isBMP

      public static boolean isBMP(int ch)
      Determines if the code point is in the BMP plane.
      Parameters:
      ch - code point to be determined if it is not a supplementary character
      Returns:
      true if code point is not a supplementary character
    • isPrintable

      public static boolean isPrintable(int ch)
      Determines whether the specified code point is a printable character according to the Unicode standard.
      Parameters:
      ch - code point to be determined if it is printable
      Returns:
      true if the code point is a printable character
    • isBaseForm

      public static boolean isBaseForm(int ch)
      Determines whether the specified code point is of base form. A code point of base form does not graphically combine with preceding characters, and is neither a control nor a format character.
      Parameters:
      ch - code point to be determined if it is of base form
      Returns:
      true if the code point is of base form
    • getDirection

      public static int getDirection(int ch)
      Returns the Bidirection property of a code point. For example, 0x0041 (letter A) has the LEFT_TO_RIGHT directional property.
      Result returned belongs to the interface UCharacterDirection
      Parameters:
      ch - the code point to be determined its direction
      Returns:
      direction constant from UCharacterDirection.
    • isMirrored

      public static boolean isMirrored(int ch)
      Determines whether the code point has the "mirrored" property. This property is set for characters that are commonly used in Right-To-Left contexts and need to be displayed with a "mirrored" glyph.
      Parameters:
      ch - code point whose mirror is to be determined
      Returns:
      true if the code point has the "mirrored" property
    • getMirror

      public static int getMirror(int ch)
      Maps the specified code point to a "mirror-image" code point. For code points with the "mirrored" property, implementations sometimes need a "poor man's" mapping to another code point such that the default glyph may serve as the mirror-image of the default glyph of the specified code point.
      This is useful for text conversion to and from codepages with visual order, and for displays without glyph selection capabilities.
      Parameters:
      ch - code point whose mirror is to be retrieved
      Returns:
      another code point that may serve as a mirror-image substitute, or ch itself if there is no such mapping or ch does not have the "mirrored" property
    • getBidiPairedBracket

      public static int getBidiPairedBracket(int c)
      Maps the specified character to its paired bracket character. For Bidi_Paired_Bracket_Type!=None, this is the same as getMirror(int). Otherwise c itself is returned. See http://www.unicode.org/reports/tr9/
      Parameters:
      c - the code point to be mapped
      Returns:
      the paired bracket code point, or c itself if there is no such mapping (Bidi_Paired_Bracket_Type=None)
      See Also:
    • getCombiningClass

      public static int getCombiningClass(int ch)
      Returns the combining class of the argument codepoint
      Parameters:
      ch - code point whose combining is to be retrieved
      Returns:
      the combining class of the codepoint
    • isLegal

      public static boolean isLegal(int ch)
      A code point is illegal if and only if
      • Out of bounds, less than 0 or greater than UCharacter.MAX_VALUE
      • A surrogate value, 0xD800 to 0xDFFF
      • Not-a-character, having the form 0x xxFFFF or 0x xxFFFE
      Note: legal does not mean that it is assigned in this version of Unicode.
      Parameters:
      ch - code point to determine if it is a legal code point by itself
      Returns:
      true if and only if legal.
    • isLegal

      public static boolean isLegal(String str)
      A string is legal iff all its code points are legal. A code point is illegal if and only if
      • Out of bounds, less than 0 or greater than UCharacter.MAX_VALUE
      • A surrogate value, 0xD800 to 0xDFFF
      • Not-a-character, having the form 0x xxFFFF or 0x xxFFFE
      Note: legal does not mean that it is assigned in this version of Unicode.
      Parameters:
      str - containing code points to examin
      Returns:
      true if and only if legal.
    • getUnicodeVersion

      public static VersionInfo getUnicodeVersion()
      Returns the version of Unicode data used.
      Returns:
      the unicode version number used
    • getName

      public static String getName(int ch)
      Returns the most current Unicode name of the argument code point, or null if the character is unassigned or outside the range UCharacter.MIN_VALUE and UCharacter.MAX_VALUE or does not have a name.
      Note calling any methods related to code point names, e.g. getName() incurs a one-time initialization cost to construct the name tables.
      Parameters:
      ch - the code point for which to get the name
      Returns:
      most current Unicode name
    • getName

      public static String getName(String s, String separator)
      Returns the names for each of the characters in a string
      Parameters:
      s - string to format
      separator - string to go between names
      Returns:
      string of names
    • getName1_0

      @Deprecated public static String getName1_0(int ch)
      Deprecated.
      ICU 49
      Returns null. Used to return the Unicode_1_Name property value which was of little practical value.
      Parameters:
      ch - the code point for which to get the name
      Returns:
      null
    • getExtendedName

      public static String getExtendedName(int ch)
      Returns a name for a valid codepoint. Unlike, getName(int) and getName1_0(int), this method will return a name even for codepoints that are not assigned a name in UnicodeData.txt.

      The names are returned in the following order.

      • Most current Unicode name if there is any
      • Unicode 1.0 name if there is any
      • Extended name in the form of "<codepoint_type-codepoint_hex_digits>". E.g., <noncharacter-fffe>
      Note calling any methods related to code point names, e.g. getName() incurs a one-time initialization cost to construct the name tables.
      Parameters:
      ch - the code point for which to get the name
      Returns:
      a name for the argument codepoint
    • getNameAlias

      public static String getNameAlias(int ch)
      Returns the corrected name from NameAliases.txt if there is one. Returns null if the character is unassigned or outside the range UCharacter.MIN_VALUE and UCharacter.MAX_VALUE or does not have a name.
      Note calling any methods related to code point names, e.g. getName() incurs a one-time initialization cost to construct the name tables.
      Parameters:
      ch - the code point for which to get the name alias
      Returns:
      Unicode name alias, or null
    • getISOComment

      @Deprecated public static String getISOComment(int ch)
      Deprecated.
      ICU 49
      Returns null. Used to return the ISO 10646 comment for a character. The Unicode ISO_Comment property is deprecated and has no values.
      Parameters:
      ch - The code point for which to get the ISO comment. It must be the case that 0 <= ch <= 0x10ffff.
      Returns:
      null
    • getCharFromName

      public static int getCharFromName(String name)

      Finds a Unicode code point by its most current Unicode name and return its code point value. All Unicode names are in uppercase. Note calling any methods related to code point names, e.g. getName() incurs a one-time initialization cost to construct the name tables.

      Parameters:
      name - most current Unicode character name whose code point is to be returned
      Returns:
      code point or -1 if name is not found
    • getCharFromName1_0

      @Deprecated public static int getCharFromName1_0(String name)
      Deprecated.
      ICU 49
      Returns -1.

      Used to find a Unicode character by its version 1.0 Unicode name and return its code point value.

      Parameters:
      name - Unicode 1.0 code point name whose code point is to be returned
      Returns:
      -1
      See Also:
    • getCharFromExtendedName

      public static int getCharFromExtendedName(String name)

      Find a Unicode character by either its name and return its code point value. All Unicode names are in uppercase. Extended names are all lowercase except for numbers and are contained within angle brackets. The names are searched in the following order

      • Most current Unicode name if there is any
      • Unicode 1.0 name if there is any
      • Extended name in the form of "<codepoint_type-codepoint_hex_digits>". E.g. <noncharacter-FFFE>
      Note calling any methods related to code point names, e.g. getName() incurs a one-time initialization cost to construct the name tables.
      Parameters:
      name - codepoint name
      Returns:
      code point associated with the name or -1 if the name is not found.
    • getCharFromNameAlias

      public static int getCharFromNameAlias(String name)

      Find a Unicode character by its corrected name alias and return its code point value. All Unicode names are in uppercase. Note calling any methods related to code point names, e.g. getName() incurs a one-time initialization cost to construct the name tables.

      Parameters:
      name - Unicode name alias whose code point is to be returned
      Returns:
      code point or -1 if name is not found
    • getPropertyName

      public static String getPropertyName(int property, int nameChoice)
      Return the Unicode name for a given property, as given in the Unicode database file PropertyAliases.txt. Most properties have more than one name. The nameChoice determines which one is returned. In addition, this function maps the property UProperty.GENERAL_CATEGORY_MASK to the synthetic names "gcm" / "General_Category_Mask". These names are not in PropertyAliases.txt.
      Parameters:
      property - UProperty selector.
      nameChoice - UProperty.NameChoice selector for which name to get. All properties have a long name. Most have a short name, but some do not. Unicode allows for additional names; if present these will be returned by UProperty.NameChoice.LONG + i, where i=1, 2,...
      Returns:
      a name, or null if Unicode explicitly defines no name ("n/a") for a given property/nameChoice. If a given nameChoice throws an exception, then all larger values of nameChoice will throw an exception. If null is returned for a given nameChoice, then other nameChoice values may return non-null results.
      Throws:
      IllegalArgumentException - thrown if property or nameChoice are invalid.
      See Also:
    • getPropertyEnum

      public static int getPropertyEnum(CharSequence propertyAlias)
      Return the UProperty selector for a given property name, as specified in the Unicode database file PropertyAliases.txt. Short, long, and any other variants are recognized. In addition, this function maps the synthetic names "gcm" / "General_Category_Mask" to the property UProperty.GENERAL_CATEGORY_MASK. These names are not in PropertyAliases.txt.
      Parameters:
      propertyAlias - the property name to be matched. The name is compared using "loose matching" as described in PropertyAliases.txt.
      Returns:
      a UProperty enum.
      Throws:
      IllegalArgumentException - thrown if propertyAlias is not recognized.
      See Also:
    • getPropertyValueName

      public static String getPropertyValueName(int property, int value, int nameChoice)
      Return the Unicode name for a given property value, as given in the Unicode database file PropertyValueAliases.txt. Most values have more than one name. The nameChoice determines which one is returned. Note: Some of the names in PropertyValueAliases.txt can only be retrieved using UProperty.GENERAL_CATEGORY_MASK, not UProperty.GENERAL_CATEGORY. These include: "C" / "Other", "L" / "Letter", "LC" / "Cased_Letter", "M" / "Mark", "N" / "Number", "P" / "Punctuation", "S" / "Symbol", and "Z" / "Separator".
      Parameters:
      property - UProperty selector constant. UProperty.INT_START <= property < UProperty.INT_LIMIT or UProperty.BINARY_START <= property < UProperty.BINARY_LIMIT or UProperty.MASK_START < = property < UProperty.MASK_LIMIT. If out of range, null is returned.
      value - selector for a value for the given property. In general, valid values range from 0 up to some maximum. There are a few exceptions: (1.) UProperty.BLOCK values begin at the non-zero value BASIC_LATIN.getID(). (2.) UProperty.CANONICAL_COMBINING_CLASS values are not contiguous and range from 0..240. (3.) UProperty.GENERAL_CATEGORY_MASK values are mask values produced by left-shifting 1 by UCharacter.getType(). This allows grouped categories such as [:L:] to be represented. Mask values are non-contiguous.
      nameChoice - UProperty.NameChoice selector for which name to get. All values have a long name. Most have a short name, but some do not. Unicode allows for additional names; if present these will be returned by UProperty.NameChoice.LONG + i, where i=1, 2,...
      Returns:
      a name, or null if Unicode explicitly defines no name ("n/a") for a given property/value/nameChoice. If a given nameChoice throws an exception, then all larger values of nameChoice will throw an exception. If null is returned for a given nameChoice, then other nameChoice values may return non-null results.
      Throws:
      IllegalArgumentException - thrown if property, value, or nameChoice are invalid.
      See Also:
    • getPropertyValueEnum

      public static int getPropertyValueEnum(int property, CharSequence valueAlias)
      Return the property value integer for a given value name, as specified in the Unicode database file PropertyValueAliases.txt. Short, long, and any other variants are recognized. Note: Some of the names in PropertyValueAliases.txt will only be recognized with UProperty.GENERAL_CATEGORY_MASK, not UProperty.GENERAL_CATEGORY. These include: "C" / "Other", "L" / "Letter", "LC" / "Cased_Letter", "M" / "Mark", "N" / "Number", "P" / "Punctuation", "S" / "Symbol", and "Z" / "Separator".
      Parameters:
      property - UProperty selector constant. UProperty.INT_START <= property < UProperty.INT_LIMIT or UProperty.BINARY_START <= property < UProperty.BINARY_LIMIT or UProperty.MASK_START < = property < UProperty.MASK_LIMIT. Only these properties can be enumerated.
      valueAlias - the value name to be matched. The name is compared using "loose matching" as described in PropertyValueAliases.txt.
      Returns:
      a value integer. Note: UProperty.GENERAL_CATEGORY values are mask values produced by left-shifting 1 by UCharacter.getType(). This allows grouped categories such as [:L:] to be represented.
      Throws:
      IllegalArgumentException - if property is not a valid UProperty selector or valueAlias is not a value of this property
      See Also:
    • getPropertyValueEnumNoThrow

      @Deprecated public static int getPropertyValueEnumNoThrow(int property, CharSequence valueAlias)
      Deprecated.
      This API is ICU internal only.
      Same as getPropertyValueEnum(int, CharSequence), except doesn't throw exception. Instead, returns UProperty.UNDEFINED.
      Parameters:
      property - Same as getPropertyValueEnum(int, CharSequence)
      valueAlias - Same as getPropertyValueEnum(int, CharSequence)
      Returns:
      returns UProperty.UNDEFINED if the value is not valid, otherwise the value.
    • getCodePoint

      public static int getCodePoint(int lead, int trail)
      Returns a code point corresponding to the two surrogate code units.
      Parameters:
      lead - the lead unit (In ICU 2.1-69 the type of both parameters was char.)
      trail - the trail unit
      Returns:
      code point if lead and trail form a valid surrogate pair.
      Throws:
      IllegalArgumentException - thrown when the code units do not form a valid surrogate pair
      See Also:
    • getCodePoint

      public static int getCodePoint(char char16)
      Returns the code point corresponding to the BMP code point.
      Parameters:
      char16 - the BMP code point
      Returns:
      code point if argument is a valid character.
      Throws:
      IllegalArgumentException - thrown when char16 is not a valid code point
    • toUpperCase

      public static String toUpperCase(String str)
      Returns the uppercase version of the argument string. Casing is dependent on the default locale and context-sensitive.
      Parameters:
      str - source string to be performed on
      Returns:
      uppercase version of the argument string
    • toLowerCase

      public static String toLowerCase(String str)
      Returns the lowercase version of the argument string. Casing is dependent on the default locale and context-sensitive
      Parameters:
      str - source string to be performed on
      Returns:
      lowercase version of the argument string
    • toTitleCase

      public static String toTitleCase(String str, BreakIterator breakiter)

      Returns the titlecase version of the argument string.

      Position for titlecasing is determined by the argument break iterator, hence the user can customize his break iterator for a specialized titlecasing. In this case only the forward iteration needs to be implemented. If the break iterator passed in is null, the default Unicode algorithm will be used to determine the titlecase positions.

      Only positions returned by the break iterator will be title cased, character in between the positions will all be in lower case.

      Casing is dependent on the default locale and context-sensitive

      Parameters:
      str - source string to be performed on
      breakiter - break iterator to determine the positions in which the character should be title cased.
      Returns:
      titlecase version of the argument string
    • toUpperCase

      public static String toUpperCase(Locale locale, String str)
      Returns the uppercase version of the argument string. Casing is dependent on the argument locale and context-sensitive.
      Parameters:
      locale - which string is to be converted in
      str - source string to be performed on
      Returns:
      uppercase version of the argument string
    • toUpperCase

      public static String toUpperCase(ULocale locale, String str)
      Returns the uppercase version of the argument string. Casing is dependent on the argument locale and context-sensitive.
      Parameters:
      locale - which string is to be converted in
      str - source string to be performed on
      Returns:
      uppercase version of the argument string
    • toLowerCase

      public static String toLowerCase(Locale locale, String str)
      Returns the lowercase version of the argument string. Casing is dependent on the argument locale and context-sensitive
      Parameters:
      locale - which string is to be converted in
      str - source string to be performed on
      Returns:
      lowercase version of the argument string
    • toLowerCase

      public static String toLowerCase(ULocale locale, String str)
      Returns the lowercase version of the argument string. Casing is dependent on the argument locale and context-sensitive
      Parameters:
      locale - which string is to be converted in
      str - source string to be performed on
      Returns:
      lowercase version of the argument string
    • toTitleCase

      public static String toTitleCase(Locale locale, String str, BreakIterator breakiter)

      Returns the titlecase version of the argument string.

      Position for titlecasing is determined by the argument break iterator, hence the user can customize his break iterator for a specialized titlecasing. In this case only the forward iteration needs to be implemented. If the break iterator passed in is null, the default Unicode algorithm will be used to determine the titlecase positions.

      Only positions returned by the break iterator will be title cased, character in between the positions will all be in lower case.

      Casing is dependent on the argument locale and context-sensitive

      Parameters:
      locale - which string is to be converted in
      str - source string to be performed on
      breakiter - break iterator to determine the positions in which the character should be title cased.
      Returns:
      titlecase version of the argument string
    • toTitleCase

      public static String toTitleCase(ULocale locale, String str, BreakIterator titleIter)

      Returns the titlecase version of the argument string.

      Position for titlecasing is determined by the argument break iterator, hence the user can customize his break iterator for a specialized titlecasing. In this case only the forward iteration needs to be implemented. If the break iterator passed in is null, the default Unicode algorithm will be used to determine the titlecase positions.

      Only positions returned by the break iterator will be title cased, character in between the positions will all be in lower case.

      Casing is dependent on the argument locale and context-sensitive

      Parameters:
      locale - which string is to be converted in
      str - source string to be performed on
      titleIter - break iterator to determine the positions in which the character should be title cased.
      Returns:
      titlecase version of the argument string
    • toTitleCase

      public static String toTitleCase(ULocale locale, String str, BreakIterator titleIter, int options)

      Returns the titlecase version of the argument string.

      Position for titlecasing is determined by the argument break iterator, hence the user can customize his break iterator for a specialized titlecasing. In this case only the forward iteration needs to be implemented. If the break iterator passed in is null, the default Unicode algorithm will be used to determine the titlecase positions.

      Only positions returned by the break iterator will be title cased, character in between the positions will all be in lower case.

      Casing is dependent on the argument locale and context-sensitive

      Parameters:
      locale - which string is to be converted in
      str - source string to be performed on
      titleIter - break iterator to determine the positions in which the character should be title cased.
      options - bit set to modify the titlecasing operation
      Returns:
      titlecase version of the argument string
      See Also:
    • toTitleCase

      public static String toTitleCase(Locale locale, String str, BreakIterator titleIter, int options)

      Returns the titlecase version of the argument string.

      Position for titlecasing is determined by the argument break iterator, hence the user can customize his break iterator for a specialized titlecasing. In this case only the forward iteration needs to be implemented. If the break iterator passed in is null, the default Unicode algorithm will be used to determine the titlecase positions.

      Only positions returned by the break iterator will be title cased, character in between the positions will all be in lower case.

      Casing is dependent on the argument locale and context-sensitive

      Parameters:
      locale - which string is to be converted in
      str - source string to be performed on
      titleIter - break iterator to determine the positions in which the character should be title cased.
      options - bit set to modify the titlecasing operation
      Returns:
      titlecase version of the argument string
      See Also:
    • foldCase

      public static int foldCase(int ch, boolean defaultmapping)
      The given character is mapped to its case folding equivalent according to UnicodeData.txt and CaseFolding.txt; if the character has no case folding equivalent, the character itself is returned.

      This function only returns the simple, single-code point case mapping. Full case mappings should be used whenever possible because they produce better results by working on whole strings. They can map to a result string with a different length as appropriate. Full case mappings are applied by the case mapping functions that take String parameters rather than code points (int). See also the User Guide chapter on C/POSIX migration: https://unicode-org.github.io/icu/userguide/icu/posix#case-mappings

      Parameters:
      ch - the character to be converted
      defaultmapping - Indicates whether the default mappings defined in CaseFolding.txt are to be used, otherwise the mappings for dotted I and dotless i marked with 'T' in CaseFolding.txt are included.
      Returns:
      the case folding equivalent of the character, if any; otherwise the character itself.
      See Also:
    • foldCase

      public static String foldCase(String str, boolean defaultmapping)
      The given string is mapped to its case folding equivalent according to UnicodeData.txt and CaseFolding.txt; if any character has no case folding equivalent, the character itself is returned. "Full", multiple-code point case folding mappings are returned here. For "simple" single-code point mappings use the API foldCase(int ch, boolean defaultmapping).
      Parameters:
      str - the String to be converted
      defaultmapping - Indicates whether the default mappings defined in CaseFolding.txt are to be used, otherwise the mappings for dotted I and dotless i marked with 'T' in CaseFolding.txt are included.
      Returns:
      the case folding equivalent of the character, if any; otherwise the character itself.
      See Also:
    • foldCase

      public static int foldCase(int ch, int options)
      The given character is mapped to its case folding equivalent according to UnicodeData.txt and CaseFolding.txt; if the character has no case folding equivalent, the character itself is returned.

      This function only returns the simple, single-code point case mapping. Full case mappings should be used whenever possible because they produce better results by working on whole strings. They can map to a result string with a different length as appropriate. Full case mappings are applied by the case mapping functions that take String parameters rather than code points (int). See also the User Guide chapter on C/POSIX migration: https://unicode-org.github.io/icu/userguide/icu/posix#case-mappings

      Parameters:
      ch - the character to be converted
      options - A bit set for special processing. Currently the recognised options are FOLD_CASE_EXCLUDE_SPECIAL_I and FOLD_CASE_DEFAULT
      Returns:
      the case folding equivalent of the character, if any; otherwise the character itself.
      See Also:
    • foldCase

      public static final String foldCase(String str, int options)
      The given string is mapped to its case folding equivalent according to UnicodeData.txt and CaseFolding.txt; if any character has no case folding equivalent, the character itself is returned. "Full", multiple-code point case folding mappings are returned here. For "simple" single-code point mappings use the API foldCase(int ch, boolean defaultmapping).
      Parameters:
      str - the String to be converted
      options - A bit set for special processing. Currently the recognised options are FOLD_CASE_EXCLUDE_SPECIAL_I and FOLD_CASE_DEFAULT
      Returns:
      the case folding equivalent of the character, if any; otherwise the character itself.
      See Also:
    • getHanNumericValue

      public static int getHanNumericValue(int ch)
      Returns the numeric value of a Han character.

      This returns the value of Han 'numeric' code points, including those for zero, ten, hundred, thousand, ten thousand, and hundred million. This includes both the standard and 'checkwriting' characters, the 'big circle' zero character, and the standard zero character.

      Note: The Unicode Standard has numeric values for more Han characters recognized by this method (see getNumericValue(int) and the UCD file DerivedNumericValues.txt), and a NumberFormat can be used with a Chinese NumberingSystem.

      Parameters:
      ch - code point to query
      Returns:
      value if it is a Han 'numeric character,' otherwise return -1.
    • getTypeIterator

      public static RangeValueIterator getTypeIterator()

      Returns an iterator for character types, iterating over codepoints.

      Example of use:

       RangeValueIterator iterator = UCharacter.getTypeIterator();
       RangeValueIterator.Element element = new RangeValueIterator.Element();
       while (iterator.next(element)) {
           System.out.println("Codepoint \\u" +
                              Integer.toHexString(element.start) +
                              " to codepoint \\u" +
                              Integer.toHexString(element.limit - 1) +
                              " has the character type " +
                              element.value);
       }
       
      Returns:
      an iterator
    • getNameIterator

      public static ValueIterator getNameIterator()

      Returns an iterator for character names, iterating over codepoints.

      This API only gets the iterator for the modern, most up-to-date Unicode names. For older 1.0 Unicode names use get1_0NameIterator() or for extended names use getExtendedNameIterator().

      Example of use:

       ValueIterator iterator = UCharacter.getNameIterator();
       ValueIterator.Element element = new ValueIterator.Element();
       while (iterator.next(element)) {
           System.out.println("Codepoint \\u" +
                              Integer.toHexString(element.codepoint) +
                              " has the name " + (String)element.value);
       }
       

      The maximal range which the name iterator iterates is from UCharacter.MIN_VALUE to UCharacter.MAX_VALUE.

      Returns:
      an iterator
    • getName1_0Iterator

      @Deprecated public static ValueIterator getName1_0Iterator()
      Deprecated.
      ICU 49
      Returns an empty iterator.

      Used to return an iterator for the older 1.0 Unicode character names, iterating over codepoints.

      Returns:
      an empty iterator
      See Also:
    • getExtendedNameIterator

      public static ValueIterator getExtendedNameIterator()

      Returns an iterator for character names, iterating over codepoints.

      This API only gets the iterator for the extended names. For modern, most up-to-date Unicode names use getNameIterator() or for older 1.0 Unicode names use get1_0NameIterator().

      Example of use:

       ValueIterator iterator = UCharacter.getExtendedNameIterator();
       ValueIterator.Element element = new ValueIterator.Element();
       while (iterator.next(element)) {
           System.out.println("Codepoint \\u" +
                              Integer.toHexString(element.codepoint) +
                              " has the name " + (String)element.value);
       }
       

      The maximal range which the name iterator iterates is from

      Returns:
      an iterator
    • getAge

      public static VersionInfo getAge(int ch)
      Returns the "age" of the code point.

      The "age" is the Unicode version when the code point was first designated (as a non-character or for Private Use) or assigned a character.

      This can be useful to avoid emitting code points to receiving processes that do not accept newer characters.

      The data is from the UCD file DerivedAge.txt.

      Parameters:
      ch - The code point.
      Returns:
      the Unicode version number
    • hasBinaryProperty

      public static boolean hasBinaryProperty(int ch, int property)
      Check a binary Unicode property for a code point.

      Unicode, especially in version 3.2, defines many more properties than the original set in UnicodeData.txt.

      This API is intended to reflect Unicode properties as defined in the Unicode Character Database (UCD) and Unicode Technical Reports (UTR).

      For details about the properties see http://www.unicode.org/.

      For names of Unicode properties see the UCD file PropertyAliases.txt.

      This API does not check the validity of the codepoint.

      Important: If ICU is built with UCD files from Unicode versions below 3.2, then properties marked with "new" are not or not fully available.

      Parameters:
      ch - code point to test.
      property - selector constant from com.ibm.icu.lang.UProperty, identifies which binary property to check.
      Returns:
      true or false according to the binary Unicode property value for ch. Also false if property is out of bounds or if the Unicode version does not have data for the property at all, or not for this code point.
      See Also:
    • hasBinaryProperty

      public static boolean hasBinaryProperty(CharSequence s, int property)
      Returns true if the property is true for the string. Same as hasBinaryProperty(int, int) if the string contains exactly one code point.

      Most properties apply only to single code points. UTS #51 Unicode Emoji defines several properties of strings.

      Parameters:
      s - String to test.
      property - UProperty selector constant, identifies which binary property to check. Must be BINARY_START<=which<BINARY_LIMIT.
      Returns:
      true or false according to the binary Unicode property value for the string. Also false if property is out of bounds or if the Unicode version does not have data for the property at all.
      See Also:
    • isUAlphabetic

      public static boolean isUAlphabetic(int ch)

      Check if a code point has the Alphabetic Unicode property.

      Same as UCharacter.hasBinaryProperty(ch, UProperty.ALPHABETIC).

      Different from UCharacter.isLetter(ch)!

      Parameters:
      ch - codepoint to be tested
    • isULowercase

      public static boolean isULowercase(int ch)

      Check if a code point has the Lowercase Unicode property.

      Same as UCharacter.hasBinaryProperty(ch, UProperty.LOWERCASE).

      This is different from UCharacter.isLowerCase(ch)!

      Parameters:
      ch - codepoint to be tested
    • isUUppercase

      public static boolean isUUppercase(int ch)

      Check if a code point has the Uppercase Unicode property.

      Same as UCharacter.hasBinaryProperty(ch, UProperty.UPPERCASE).

      This is different from UCharacter.isUpperCase(ch)!

      Parameters:
      ch - codepoint to be tested
    • isUWhiteSpace

      public static boolean isUWhiteSpace(int ch)

      Check if a code point has the White_Space Unicode property.

      Same as UCharacter.hasBinaryProperty(ch, UProperty.WHITE_SPACE).

      This is different from both UCharacter.isSpace(ch) and UCharacter.isWhitespace(ch)!

      Parameters:
      ch - codepoint to be tested
    • getIntPropertyValue

      public static int getIntPropertyValue(int ch, int type)
      Returns the property value for a Unicode property type of a code point. Also returns binary and mask property values.

      Unicode, especially in version 3.2, defines many more properties than the original set in UnicodeData.txt.

      The properties APIs are intended to reflect Unicode properties as defined in the Unicode Character Database (UCD) and Unicode Technical Reports (UTR). For details about the properties see http://www.unicode.org/.

      For names of Unicode properties see the UCD file PropertyAliases.txt.

       Sample usage:
       int ea = UCharacter.getIntPropertyValue(c, UProperty.EAST_ASIAN_WIDTH);
       int ideo = UCharacter.getIntPropertyValue(c, UProperty.IDEOGRAPHIC);
       boolean b = (ideo == 1) ? true : false;
       
      Parameters:
      ch - code point to test.
      type - UProperty selector constant, identifies which binary property to check. Must be UProperty.BINARY_START <= type < UProperty.BINARY_LIMIT or UProperty.INT_START <= type < UProperty.INT_LIMIT or UProperty.MASK_START <= type < UProperty.MASK_LIMIT.
      Returns:
      numeric value that is directly the property value or, for enumerated properties, corresponds to the numeric value of the enumerated constant of the respective property value type (UCharacterEnums.ECharacterCategory, UCharacterEnums.ECharacterDirection, UCharacter.DecompositionType, etc.). Returns 0 or 1 (for false / true) for binary Unicode properties. Returns a bit-mask for mask properties. Returns 0 if 'type' is out of bounds or if the Unicode version does not have data for the property at all, or not for this code point.
      See Also:
    • getStringPropertyValue

      @Deprecated public static String getStringPropertyValue(int propertyEnum, int codepoint, int nameChoice)
      Deprecated.
      This API is ICU internal only.
      Returns a string version of the property value.
      Parameters:
      propertyEnum - The property enum value.
      codepoint - The codepoint value.
      nameChoice - The choice of the name.
      Returns:
      value as string
    • getIntPropertyMinValue

      public static int getIntPropertyMinValue(int type)
      Returns the minimum value for an integer/binary Unicode property type. Can be used together with UCharacter.getIntPropertyMaxValue(int) to allocate arrays of com.ibm.icu.text.UnicodeSet or similar.
      Parameters:
      type - UProperty selector constant, identifies which binary property to check. Must be UProperty.BINARY_START <= type < UProperty.BINARY_LIMIT or UProperty.INT_START <= type < UProperty.INT_LIMIT.
      Returns:
      Minimum value returned by UCharacter.getIntPropertyValue(int) for a Unicode property. 0 if the property selector 'type' is out of range.
      See Also:
    • getIntPropertyMaxValue

      public static int getIntPropertyMaxValue(int type)
      Returns the maximum value for an integer/binary Unicode property. Can be used together with UCharacter.getIntPropertyMinValue(int) to allocate arrays of com.ibm.icu.text.UnicodeSet or similar. Examples for min/max values (for Unicode 3.2):
      • UProperty.BIDI_CLASS: 0/18 (UCharacterDirection.LEFT_TO_RIGHT/UCharacterDirection.BOUNDARY_NEUTRAL)
      • UProperty.SCRIPT: 0/45 (UScript.COMMON/UScript.TAGBANWA)
      • UProperty.IDEOGRAPHIC: 0/1 (false/true)
      For undefined UProperty constant values, min/max values will be 0/-1.
      Parameters:
      type - UProperty selector constant, identifies which binary property to check. Must be UProperty.BINARY_START <= type < UProperty.BINARY_LIMIT or UProperty.INT_START <= type < UProperty.INT_LIMIT.
      Returns:
      Maximum value returned by u_getIntPropertyValue for a Unicode property. <= 0 if the property selector 'type' is out of range.
      See Also:
    • forDigit

      public static char forDigit(int digit, int radix)
      Provide the java.lang.Character forDigit API, for convenience.
    • isValidCodePoint

      public static final boolean isValidCodePoint(int cp)
      Parameters:
      cp - the code point to check
      Returns:
      true if cp is a valid code point
    • isSupplementaryCodePoint

      public static final boolean isSupplementaryCodePoint(int cp)
      Parameters:
      cp - the code point to check
      Returns:
      true if cp is a supplementary code point
    • isHighSurrogate

      public static boolean isHighSurrogate(int codePoint)
      Same as Character.isHighSurrogate(char), except that the ICU version accepts int for code points.
      Parameters:
      codePoint - the code point to check (In ICU 3.0-69 the type of this parameter was char.)
      Returns:
      true if codePoint is a high (lead) surrogate
    • isLowSurrogate

      public static boolean isLowSurrogate(int codePoint)
      Same as Character.isLowSurrogate(char), except that the ICU version accepts int for code points.
      Parameters:
      codePoint - the code point to check (In ICU 3.0-69 the type of this parameter was char.)
      Returns:
      true if codePoint is a low (trail) surrogate
    • isSurrogatePair

      public static final boolean isSurrogatePair(int high, int low)
      Same as Character.isSurrogatePair(char, char), except that the ICU version accepts int for code points.
      Parameters:
      high - the high (lead) unit (In ICU 3.0-69 the type of both parameters was char.)
      low - the low (trail) unit
      Returns:
      true if high, low form a surrogate pair
    • charCount

      public static int charCount(int cp)
      Same as Character.charCount(int). Returns the number of chars needed to represent the code point (1 or 2). This does not check the code point for validity.
      Parameters:
      cp - the code point to check
      Returns:
      the number of chars needed to represent the code point
    • toCodePoint

      public static final int toCodePoint(int high, int low)
      Same as Character.toCodePoint(char, char), except that the ICU version accepts int for code points. Returns the code point represented by the two surrogate code units. This does not check the surrogate pair for validity.
      Parameters:
      high - the high (lead) surrogate (In ICU 3.0-69 the type of both parameters was char.)
      low - the low (trail) surrogate
      Returns:
      the code point formed by the surrogate pair
      See Also:
    • codePointAt

      public static final int codePointAt(CharSequence seq, int index)
      Same as Character.codePointAt(CharSequence, int). Returns the code point at index. This examines only the characters at index and index+1.
      Parameters:
      seq - the characters to check
      index - the index of the first or only char forming the code point
      Returns:
      the code point at the index
    • codePointAt

      public static final int codePointAt(char[] text, int index)
      Same as Character.codePointAt(char[], int). Returns the code point at index. This examines only the characters at index and index+1.
      Parameters:
      text - the characters to check
      index - the index of the first or only char forming the code point
      Returns:
      the code point at the index
    • codePointAt

      public static final int codePointAt(char[] text, int index, int limit)
      Same as Character.codePointAt(char[], int, int). Returns the code point at index. This examines only the characters at index and index+1.
      Parameters:
      text - the characters to check
      index - the index of the first or only char forming the code point
      limit - the limit of the valid text
      Returns:
      the code point at the index
    • codePointBefore

      public static final int codePointBefore(CharSequence seq, int index)
      Same as Character.codePointBefore(CharSequence, int). Return the code point before index. This examines only the characters at index-1 and index-2.
      Parameters:
      seq - the characters to check
      index - the index after the last or only char forming the code point
      Returns:
      the code point before the index
    • codePointBefore

      public static final int codePointBefore(char[] text, int index)
      Same as Character.codePointBefore(char[], int). Returns the code point before index. This examines only the characters at index-1 and index-2.
      Parameters:
      text - the characters to check
      index - the index after the last or only char forming the code point
      Returns:
      the code point before the index
    • codePointBefore

      public static final int codePointBefore(char[] text, int index, int limit)
      Same as Character.codePointBefore(char[], int, int). Return the code point before index. This examines only the characters at index-1 and index-2.
      Parameters:
      text - the characters to check
      index - the index after the last or only char forming the code point
      limit - the start of the valid text
      Returns:
      the code point before the index
    • toChars

      public static final int toChars(int cp, char[] dst, int dstIndex)
      Same as Character.toChars(int, char[], int). Writes the chars representing the code point into the destination at the given index.
      Parameters:
      cp - the code point to convert
      dst - the destination array into which to put the char(s) representing the code point
      dstIndex - the index at which to put the first (or only) char
      Returns:
      the count of the number of chars written (1 or 2)
      Throws:
      IllegalArgumentException - if cp is not a valid code point
    • toChars

      public static final char[] toChars(int cp)
      Same as Character.toChars(int). Returns a char array representing the code point.
      Parameters:
      cp - the code point to convert
      Returns:
      an array containing the char(s) representing the code point
      Throws:
      IllegalArgumentException - if cp is not a valid code point
    • getDirectionality

      public static byte getDirectionality(int cp)
      Equivalent to the Character.getDirectionality(char) method, for convenience. Returns a byte representing the directionality of the character. Unlike Character.getDirectionality(char), this returns DIRECTIONALITY_LEFT_TO_RIGHT for undefined or out-of-bounds characters. The return value must be tested using the constants defined in UCharacterDirection and its interface UCharacterEnums.ECharacterDirection since the values are different from the ones defined by java.lang.Character.
      Parameters:
      cp - the code point to check
      Returns:
      the directionality of the code point
      See Also:
    • codePointCount

      public static int codePointCount(CharSequence text, int start, int limit)
      Equivalent to the Character.codePointCount(CharSequence, int, int) method, for convenience. Counts the number of code points in the range of text.
      Parameters:
      text - the characters to check
      start - the start of the range
      limit - the limit of the range
      Returns:
      the number of code points in the range
    • codePointCount

      public static int codePointCount(char[] text, int start, int limit)
      Equivalent to the Character.codePointCount(char[], int, int) method, for convenience. Counts the number of code points in the range of text.
      Parameters:
      text - the characters to check
      start - the start of the range
      limit - the limit of the range
      Returns:
      the number of code points in the range
    • offsetByCodePoints

      public static int offsetByCodePoints(CharSequence text, int index, int codePointOffset)
      Equivalent to the Character.offsetByCodePoints(CharSequence, int, int) method, for convenience. Adjusts the char index by a code point offset.
      Parameters:
      text - the characters to check
      index - the index to adjust
      codePointOffset - the number of code points by which to offset the index
      Returns:
      the adjusted index
    • offsetByCodePoints

      public static int offsetByCodePoints(char[] text, int start, int count, int index, int codePointOffset)
      Equivalent to the Character.offsetByCodePoints(char[], int, int, int, int) method, for convenience. Adjusts the char index by a code point offset.
      Parameters:
      text - the characters to check
      start - the start of the range to check
      count - the length of the range to check
      index - the index to adjust
      codePointOffset - the number of code points by which to offset the index
      Returns:
      the adjusted index