Serializable
, Comparable<Character>
, Constable
public final class Character extends Object implements Serializable, Comparable<Character>, Constable
Character
class wraps a value of the primitive type char
in an object. An object of class Character
contains a single field whose type is char
. In addition, this class provides a large number of static methods for determining a character's category (lowercase letter, digit, etc.) and for converting characters from uppercase to lowercase and vice versa.
The fields and methods of class Character
are defined in terms of character information from the Unicode Standard, specifically the UnicodeData file that is part of the Unicode Character Database. This file specifies properties including name and category for every assigned Unicode code point or character range. The file is available from the Unicode Consortium at http://www.unicode.org.
Character information is based on the Unicode Standard, version 15.0.
The Java platform has supported different versions of the Unicode Standard over time. Upgrades to newer versions of the Unicode Standard occurred in the following Java releases, each indicating the new version:
Java release | Unicode version |
---|---|
Java SE 20 | Unicode 15.0 |
Java SE 19 | Unicode 14.0 |
Java SE 15 | Unicode 13.0 |
Java SE 13 | Unicode 12.1 |
Java SE 12 | Unicode 11.0 |
Java SE 11 | Unicode 10.0 |
Java SE 9 | Unicode 8.0 |
Java SE 8 | Unicode 6.2 |
Java SE 7 | Unicode 6.0 |
Java SE 5.0 | Unicode 4.0 |
Java SE 1.4 | Unicode 3.0 |
JDK 1.1 | Unicode 2.0 |
JDK 1.0.2 | Unicode 1.1.5 |
The char
data type (and therefore the value that a Character
object encapsulates) are based on the original Unicode specification, which defined characters as fixed-width 16-bit entities. The Unicode Standard has since been changed to allow for characters whose representation requires more than 16 bits. The range of legal code points is now U+0000 to U+10FFFF, known as Unicode scalar value. (Refer to the definition of the U+n notation in the Unicode Standard.)
The set of characters from U+0000 to U+FFFF is sometimes referred to as the Basic Multilingual Plane (BMP). Characters whose code points are greater than U+FFFF are called supplementary characters. The Java platform uses the UTF-16 representation in char
arrays and in the String
and StringBuffer
classes. In this representation, supplementary characters are represented as a pair of char
values, the first from the high-surrogates range, (\uD800-\uDBFF), the second from the low-surrogates range (\uDC00-\uDFFF).
A char
value, therefore, represents Basic Multilingual Plane (BMP) code points, including the surrogate code points, or code units of the UTF-16 encoding. An int
value represents all Unicode code points, including supplementary code points. The lower (least significant) 21 bits of int
are used to represent Unicode code points and the upper (most significant) 11 bits must be zero. Unless otherwise specified, the behavior with respect to supplementary characters and surrogate char
values is as follows:
char
value cannot support supplementary characters. They treat char
values from the surrogate ranges as undefined characters. For example, Character.isLetter('\uD840')
returns false
, even though this specific value if followed by any low-surrogate value in a string would represent a letter. int
value support all Unicode characters, including supplementary characters. For example, Character.isLetter(0x2F81A)
returns true
because the code point value represents a letter (a CJK ideograph). In the Java SE API documentation, Unicode code point is used for character values in the range between U+0000 and U+10FFFF, and Unicode code unit is used for 16-bit char
values that are code units of the UTF-16 encoding. For more information on Unicode terminology, refer to the Unicode Glossary.
This is a value-based class; programmers should treat instances that are equal as interchangeable and should not use instances for synchronization, or unpredictable behavior may occur. For example, in a future release, synchronization may fail.
Modifier and Type | Class | Description |
---|---|---|
static class |
Character.Subset |
Instances of this class represent particular subsets of the Unicode character set. |
static final class |
Character.UnicodeBlock |
A family of character subsets representing the character blocks in the Unicode specification. |
static enum |
Character.UnicodeScript |
A family of character subsets representing the character scripts defined in the Unicode Standard Annex #24: Script Names. |
Modifier and Type | Field | Description |
---|---|---|
static final int |
BYTES |
The number of bytes used to represent a char value in unsigned binary form. |
static final byte |
COMBINING_SPACING_MARK |
General category "Mc" in the Unicode specification. |
static final byte |
CONNECTOR_PUNCTUATION |
General category "Pc" in the Unicode specification. |
static final byte |
CONTROL |
General category "Cc" in the Unicode specification. |
static final byte |
CURRENCY_SYMBOL |
General category "Sc" in the Unicode specification. |
static final byte |
DASH_PUNCTUATION |
General category "Pd" in the Unicode specification. |
static final byte |
DECIMAL_DIGIT_NUMBER |
General category "Nd" in the Unicode specification. |
static final byte |
DIRECTIONALITY_ARABIC_NUMBER |
Weak bidirectional character type "AN" in the Unicode specification. |
static final byte |
DIRECTIONALITY_BOUNDARY_NEUTRAL |
Weak bidirectional character type "BN" in the Unicode specification. |
static final byte |
DIRECTIONALITY_COMMON_NUMBER_SEPARATOR |
Weak bidirectional character type "CS" in the Unicode specification. |
static final byte |
DIRECTIONALITY_EUROPEAN_NUMBER |
Weak bidirectional character type "EN" in the Unicode specification. |
static final byte |
DIRECTIONALITY_EUROPEAN_NUMBER_SEPARATOR |
Weak bidirectional character type "ES" in the Unicode specification. |
static final byte |
DIRECTIONALITY_EUROPEAN_NUMBER_TERMINATOR |
Weak bidirectional character type "ET" in the Unicode specification. |
static final byte |
DIRECTIONALITY_FIRST_STRONG_ISOLATE |
Weak bidirectional character type "FSI" in the Unicode specification. |
static final byte |
DIRECTIONALITY_LEFT_TO_RIGHT |
Strong bidirectional character type "L" in the Unicode specification. |
static final byte |
DIRECTIONALITY_LEFT_TO_RIGHT_EMBEDDING |
Strong bidirectional character type "LRE" in the Unicode specification. |
static final byte |
DIRECTIONALITY_LEFT_TO_RIGHT_ISOLATE |
Weak bidirectional character type "LRI" in the Unicode specification. |
static final byte |
DIRECTIONALITY_LEFT_TO_RIGHT_OVERRIDE |
Strong bidirectional character type "LRO" in the Unicode specification. |
static final byte |
DIRECTIONALITY_NONSPACING_MARK |
Weak bidirectional character type "NSM" in the Unicode specification. |
static final byte |
DIRECTIONALITY_OTHER_NEUTRALS |
Neutral bidirectional character type "ON" in the Unicode specification. |
static final byte |
DIRECTIONALITY_PARAGRAPH_SEPARATOR |
Neutral bidirectional character type "B" in the Unicode specification. |
static final byte |
DIRECTIONALITY_POP_DIRECTIONAL_FORMAT |
Weak bidirectional character type "PDF" in the Unicode specification. |
static final byte |
DIRECTIONALITY_POP_DIRECTIONAL_ISOLATE |
Weak bidirectional character type "PDI" in the Unicode specification. |
static final byte |
DIRECTIONALITY_RIGHT_TO_LEFT |
Strong bidirectional character type "R" in the Unicode specification. |
static final byte |
DIRECTIONALITY_RIGHT_TO_LEFT_ARABIC |
Strong bidirectional character type "AL" in the Unicode specification. |
static final byte |
DIRECTIONALITY_RIGHT_TO_LEFT_EMBEDDING |
Strong bidirectional character type "RLE" in the Unicode specification. |
static final byte |
DIRECTIONALITY_RIGHT_TO_LEFT_ISOLATE |
Weak bidirectional character type "RLI" in the Unicode specification. |
static final byte |
DIRECTIONALITY_RIGHT_TO_LEFT_OVERRIDE |
Strong bidirectional character type "RLO" in the Unicode specification. |
static final byte |
DIRECTIONALITY_SEGMENT_SEPARATOR |
Neutral bidirectional character type "S" in the Unicode specification. |
static final byte |
DIRECTIONALITY_UNDEFINED |
Undefined bidirectional character type. |
static final byte |
DIRECTIONALITY_WHITESPACE |
Neutral bidirectional character type "WS" in the Unicode specification. |
static final byte |
ENCLOSING_MARK |
General category "Me" in the Unicode specification. |
static final byte |
END_PUNCTUATION |
General category "Pe" in the Unicode specification. |
static final byte |
FINAL_QUOTE_PUNCTUATION |
General category "Pf" in the Unicode specification. |
static final byte |
FORMAT |
General category "Cf" in the Unicode specification. |
static final byte |
INITIAL_QUOTE_PUNCTUATION |
General category "Pi" in the Unicode specification. |
static final byte |
LETTER_NUMBER |
General category "Nl" in the Unicode specification. |
static final byte |
LINE_SEPARATOR |
General category "Zl" in the Unicode specification. |
static final byte |
LOWERCASE_LETTER |
General category "Ll" in the Unicode specification. |
static final byte |
MATH_SYMBOL |
General category "Sm" in the Unicode specification. |
static final int |
MAX_CODE_POINT |
The maximum value of a Unicode code point, constant U+10FFFF . |
static final char |
MAX_HIGH_SURROGATE |
The maximum value of a Unicode high-surrogate code unit in the UTF-16 encoding, constant '\uDBFF' . |
static final char |
MAX_LOW_SURROGATE |
The maximum value of a Unicode low-surrogate code unit in the UTF-16 encoding, constant '\uDFFF' . |
static final int |
MAX_RADIX |
The maximum radix available for conversion to and from strings. |
static final char |
MAX_SURROGATE |
The maximum value of a Unicode surrogate code unit in the UTF-16 encoding, constant '\uDFFF' . |
static final char |
MAX_VALUE |
The constant value of this field is the largest value of type char , '\uFFFF' . |
static final int |
MIN_CODE_POINT |
The minimum value of a Unicode code point, constant U+0000 . |
static final char |
MIN_HIGH_SURROGATE |
The minimum value of a Unicode high-surrogate code unit in the UTF-16 encoding, constant '\uD800' . |
static final char |
MIN_LOW_SURROGATE |
The minimum value of a Unicode low-surrogate code unit in the UTF-16 encoding, constant '\uDC00' . |
static final int |
MIN_RADIX |
The minimum radix available for conversion to and from strings. |
static final int |
MIN_SUPPLEMENTARY_CODE_POINT |
The minimum value of a Unicode supplementary code point, constant U+10000 . |
static final char |
MIN_SURROGATE |
The minimum value of a Unicode surrogate code unit in the UTF-16 encoding, constant '\uD800' . |
static final char |
MIN_VALUE |
The constant value of this field is the smallest value of type char , '\u0000' . |
static final byte |
MODIFIER_LETTER |
General category "Lm" in the Unicode specification. |
static final byte |
MODIFIER_SYMBOL |
General category "Sk" in the Unicode specification. |
static final byte |
NON_SPACING_MARK |
General category "Mn" in the Unicode specification. |
static final byte |
OTHER_LETTER |
General category "Lo" in the Unicode specification. |
static final byte |
OTHER_NUMBER |
General category "No" in the Unicode specification. |
static final byte |
OTHER_PUNCTUATION |
General category "Po" in the Unicode specification. |
static final byte |
OTHER_SYMBOL |
General category "So" in the Unicode specification. |
static final byte |
PARAGRAPH_SEPARATOR |
General category "Zp" in the Unicode specification. |
static final byte |
PRIVATE_USE |
General category "Co" in the Unicode specification. |
static final int |
SIZE |
The number of bits used to represent a char value in unsigned binary form, constant 16 . |
static final byte |
SPACE_SEPARATOR |
General category "Zs" in the Unicode specification. |
static final byte |
START_PUNCTUATION |
General category "Ps" in the Unicode specification. |
static final byte |
SURROGATE |
General category "Cs" in the Unicode specification. |
static final byte |
TITLECASE_LETTER |
General category "Lt" in the Unicode specification. |
static final Class |
TYPE |
The Class instance representing the primitive type char . |
static final byte |
UNASSIGNED |
General category "Cn" in the Unicode specification. |
static final byte |
UPPERCASE_LETTER |
General category "Lu" in the Unicode specification. |
Constructor | Description |
---|---|
Character |
Deprecated, for removal: This API element is subject to removal in a future version. It is rarely appropriate to use this constructor. |
Modifier and Type | Method | Description |
---|---|---|
static int |
charCount |
Determines the number of char values needed to represent the specified character (Unicode code point). |
char |
charValue() |
Returns the value of this Character object. |
static int |
codePointAt |
Returns the code point at the given index of the char array. |
static int |
codePointAt |
Returns the code point at the given index of the char array, where only array elements with index less than limit can be used. |
static int |
codePointAt |
Returns the code point at the given index of the CharSequence . |
static int |
codePointBefore |
Returns the code point preceding the given index of the char array. |
static int |
codePointBefore |
Returns the code point preceding the given index of the char array, where only array elements with index greater than or equal to start can be used. |
static int |
codePointBefore |
Returns the code point preceding the given index of the CharSequence . |
static int |
codePointCount |
Returns the number of Unicode code points in a subarray of the char array argument. |
static int |
codePointCount |
Returns the number of Unicode code points in the text range of the specified char sequence. |
static int |
codePointOf |
Returns the code point value of the Unicode character specified by the given character name. |
static int |
compare |
Compares two char values numerically. |
int |
compareTo |
Compares two Character objects numerically. |
Optional |
describeConstable() |
Returns an Optional containing the nominal descriptor for this instance. |
static int |
digit |
Returns the numeric value of the character ch in the specified radix. |
static int |
digit |
Returns the numeric value of the specified character (Unicode code point) in the specified radix. |
boolean |
equals |
Compares this object against the specified object. |
static char |
forDigit |
Determines the character representation for a specific digit in the specified radix. |
static byte |
getDirectionality |
Returns the Unicode directionality property for the given character. |
static byte |
getDirectionality |
Returns the Unicode directionality property for the given character (Unicode code point). |
static String |
getName |
Returns the name of the specified character codePoint , or null if the code point is unassigned . |
static int |
getNumericValue |
Returns the int value that the specified Unicode character represents. |
static int |
getNumericValue |
Returns the int value that the specified character (Unicode code point) represents. |
static int |
getType |
Returns a value indicating a character's general category. |
static int |
getType |
Returns a value indicating a character's general category. |
int |
hashCode() |
Returns a hash code for this Character ; equal to the result of invoking charValue() . |
static int |
hashCode |
Returns a hash code for a char value; compatible with Character.hashCode() . |
static char |
highSurrogate |
Returns the leading surrogate (a high surrogate code unit) of the surrogate pair representing the specified supplementary character (Unicode code point) in the UTF-16 encoding. |
static boolean |
isAlphabetic |
Determines if the specified character (Unicode code point) is alphabetic. |
static boolean |
isBmpCodePoint |
Determines whether the specified character (Unicode code point) is in the Basic Multilingual Plane (BMP). |
static boolean |
isDefined |
Determines if a character is defined in Unicode. |
static boolean |
isDefined |
Determines if a character (Unicode code point) is defined in Unicode. |
static boolean |
isDigit |
Determines if the specified character is a digit. |
static boolean |
isDigit |
Determines if the specified character (Unicode code point) is a digit. |
static boolean |
isEmoji |
Determines if the specified character (Unicode code point) is an Emoji. |
static boolean |
isEmojiComponent |
Determines if the specified character (Unicode code point) is an Emoji Component. |
static boolean |
isEmojiModifier |
Determines if the specified character (Unicode code point) is an Emoji Modifier. |
static boolean |
isEmojiModifierBase |
Determines if the specified character (Unicode code point) is an Emoji Modifier Base. |
static boolean |
isEmojiPresentation |
Determines if the specified character (Unicode code point) has the Emoji Presentation property by default. |
static boolean |
isExtendedPictographic |
Determines if the specified character (Unicode code point) is an Extended Pictographic. |
static boolean |
isHighSurrogate |
Determines if the given char value is a Unicode high-surrogate code unit (also known as leading-surrogate code unit). |
static boolean |
isIdentifierIgnorable |
Determines if the specified character should be regarded as an ignorable character in a Java identifier or a Unicode identifier. |
static boolean |
isIdentifierIgnorable |
Determines if the specified character (Unicode code point) should be regarded as an ignorable character in a Java identifier or a Unicode identifier. |
static boolean |
isIdeographic |
Determines if the specified character (Unicode code point) is a CJKV (Chinese, Japanese, Korean and Vietnamese) ideograph, as defined by the Unicode Standard. |
static boolean |
isISOControl |
Determines if the specified character is an ISO control character. |
static boolean |
isISOControl |
Determines if the referenced character (Unicode code point) is an ISO control character. |
static boolean |
isJavaIdentifierPart |
Determines if the specified character may be part of a Java identifier as other than the first character. |
static boolean |
isJavaIdentifierPart |
Determines if the character (Unicode code point) may be part of a Java identifier as other than the first character. |
static boolean |
isJavaIdentifierStart |
Determines if the specified character is permissible as the first character in a Java identifier. |
static boolean |
isJavaIdentifierStart |
Determines if the character (Unicode code point) is permissible as the first character in a Java identifier. |
static boolean |
isJavaLetter |
Deprecated. Replaced by isJavaIdentifierStart(char). |
static boolean |
isJavaLetterOrDigit |
Deprecated. Replaced by isJavaIdentifierPart(char). |
static boolean |
isLetter |
Determines if the specified character is a letter. |
static boolean |
isLetter |
Determines if the specified character (Unicode code point) is a letter. |
static boolean |
isLetterOrDigit |
Determines if the specified character is a letter or digit. |
static boolean |
isLetterOrDigit |
Determines if the specified character (Unicode code point) is a letter or digit. |
static boolean |
isLowerCase |
Determines if the specified character is a lowercase character. |
static boolean |
isLowerCase |
Determines if the specified character (Unicode code point) is a lowercase character. |
static boolean |
isLowSurrogate |
Determines if the given char value is a Unicode low-surrogate code unit (also known as trailing-surrogate code unit). |
static boolean |
isMirrored |
Determines whether the character is mirrored according to the Unicode specification. |
static boolean |
isMirrored |
Determines whether the specified character (Unicode code point) is mirrored according to the Unicode specification. |
static boolean |
isSpace |
Deprecated. Replaced by isWhitespace(char). |
static boolean |
isSpaceChar |
Determines if the specified character is a Unicode space character. |
static boolean |
isSpaceChar |
Determines if the specified character (Unicode code point) is a Unicode space character. |
static boolean |
isSupplementaryCodePoint |
Determines whether the specified character (Unicode code point) is in the supplementary character range. |
static boolean |
isSurrogate |
Determines if the given char value is a Unicode surrogate code unit. |
static boolean |
isSurrogatePair |
Determines whether the specified pair of char values is a valid Unicode surrogate pair. |
static boolean |
isTitleCase |
Determines if the specified character is a titlecase character. |
static boolean |
isTitleCase |
Determines if the specified character (Unicode code point) is a titlecase character. |
static boolean |
isUnicodeIdentifierPart |
Determines if the specified character may be part of a Unicode identifier as other than the first character. |
static boolean |
isUnicodeIdentifierPart |
Determines if the specified character (Unicode code point) may be part of a Unicode identifier as other than the first character. |
static boolean |
isUnicodeIdentifierStart |
Determines if the specified character is permissible as the first character in a Unicode identifier. |
static boolean |
isUnicodeIdentifierStart |
Determines if the specified character (Unicode code point) is permissible as the first character in a Unicode identifier. |
static boolean |
isUpperCase |
Determines if the specified character is an uppercase character. |
static boolean |
isUpperCase |
Determines if the specified character (Unicode code point) is an uppercase character. |
static boolean |
isValidCodePoint |
Determines whether the specified code point is a valid Unicode code point value. |
static boolean |
isWhitespace |
Determines if the specified character is white space according to Java. |
static boolean |
isWhitespace |
Determines if the specified character (Unicode code point) is white space according to Java. |
static char |
lowSurrogate |
Returns the trailing surrogate (a low surrogate code unit) of the surrogate pair representing the specified supplementary character (Unicode code point) in the UTF-16 encoding. |
static int |
offsetByCodePoints |
Returns the index within the given char subarray that is offset from the given index by codePointOffset code points. |
static int |
offsetByCodePoints |
Returns the index within the given char sequence that is offset from the given index by codePointOffset code points. |
static char |
reverseBytes |
Returns the value obtained by reversing the order of the bytes in the specified char value. |
static char[] |
toChars |
Converts the specified character (Unicode code point) to its UTF-16 representation stored in a char array. |
static int |
toChars |
Converts the specified character (Unicode code point) to its UTF-16 representation. |
static int |
toCodePoint |
Converts the specified surrogate pair to its supplementary code point value. |
static char |
toLowerCase |
Converts the character argument to lowercase using case mapping information from the UnicodeData file. |
static int |
toLowerCase |
Converts the character (Unicode code point) argument to lowercase using case mapping information from the UnicodeData file. |
String |
toString() |
Returns a String object representing this Character 's value. |
static String |
toString |
Returns a String object representing the specified char . |
static String |
toString |
Returns a String object representing the specified character (Unicode code point). |
static char |
toTitleCase |
Converts the character argument to titlecase using case mapping information from the UnicodeData file. |
static int |
toTitleCase |
Converts the character (Unicode code point) argument to titlecase using case mapping information from the UnicodeData file. |
static char |
toUpperCase |
Converts the character argument to uppercase using case mapping information from the UnicodeData file. |
static int |
toUpperCase |
Converts the character (Unicode code point) argument to uppercase using case mapping information from the UnicodeData file. |
static Character |
valueOf |
Returns a Character instance representing the specified char value. |
public static final int MIN_RADIX
digit
method, the forDigit
method, and the toString
method of class Integer
.public static final int MAX_RADIX
digit
method, the forDigit
method, and the toString
method of class Integer
.public static final char MIN_VALUE
char
, '\u0000'
.public static final char MAX_VALUE
char
, '\uFFFF'
.public static final Class<Character> TYPE
Class
instance representing the primitive type char
.public static final byte UNASSIGNED
public static final byte UPPERCASE_LETTER
public static final byte LOWERCASE_LETTER
public static final byte TITLECASE_LETTER
public static final byte MODIFIER_LETTER
public static final byte OTHER_LETTER
public static final byte NON_SPACING_MARK
public static final byte ENCLOSING_MARK
public static final byte COMBINING_SPACING_MARK
public static final byte DECIMAL_DIGIT_NUMBER
public static final byte LETTER_NUMBER
public static final byte OTHER_NUMBER
public static final byte SPACE_SEPARATOR
public static final byte LINE_SEPARATOR
public static final byte PARAGRAPH_SEPARATOR
public static final byte CONTROL
public static final byte FORMAT
public static final byte PRIVATE_USE
public static final byte SURROGATE
public static final byte DASH_PUNCTUATION
public static final byte START_PUNCTUATION
public static final byte END_PUNCTUATION
public static final byte CONNECTOR_PUNCTUATION
public static final byte OTHER_PUNCTUATION
public static final byte MATH_SYMBOL
public static final byte CURRENCY_SYMBOL
public static final byte MODIFIER_SYMBOL
public static final byte OTHER_SYMBOL
public static final byte INITIAL_QUOTE_PUNCTUATION
public static final byte FINAL_QUOTE_PUNCTUATION
public static final byte DIRECTIONALITY_UNDEFINED
char
values have undefined directionality in the Unicode specification.public static final byte DIRECTIONALITY_LEFT_TO_RIGHT
public static final byte DIRECTIONALITY_RIGHT_TO_LEFT
public static final byte DIRECTIONALITY_RIGHT_TO_LEFT_ARABIC
public static final byte DIRECTIONALITY_EUROPEAN_NUMBER
public static final byte DIRECTIONALITY_EUROPEAN_NUMBER_SEPARATOR
public static final byte DIRECTIONALITY_EUROPEAN_NUMBER_TERMINATOR
public static final byte DIRECTIONALITY_ARABIC_NUMBER
public static final byte DIRECTIONALITY_COMMON_NUMBER_SEPARATOR
public static final byte DIRECTIONALITY_NONSPACING_MARK
public static final byte DIRECTIONALITY_BOUNDARY_NEUTRAL
public static final byte DIRECTIONALITY_PARAGRAPH_SEPARATOR
public static final byte DIRECTIONALITY_SEGMENT_SEPARATOR
public static final byte DIRECTIONALITY_WHITESPACE
public static final byte DIRECTIONALITY_OTHER_NEUTRALS
public static final byte DIRECTIONALITY_LEFT_TO_RIGHT_EMBEDDING
public static final byte DIRECTIONALITY_LEFT_TO_RIGHT_OVERRIDE
public static final byte DIRECTIONALITY_RIGHT_TO_LEFT_EMBEDDING
public static final byte DIRECTIONALITY_RIGHT_TO_LEFT_OVERRIDE
public static final byte DIRECTIONALITY_POP_DIRECTIONAL_FORMAT
public static final byte DIRECTIONALITY_LEFT_TO_RIGHT_ISOLATE
public static final byte DIRECTIONALITY_RIGHT_TO_LEFT_ISOLATE
public static final byte DIRECTIONALITY_FIRST_STRONG_ISOLATE
public static final byte DIRECTIONALITY_POP_DIRECTIONAL_ISOLATE
public static final char MIN_HIGH_SURROGATE
'\uD800'
. A high-surrogate is also known as a leading-surrogate.public static final char MAX_HIGH_SURROGATE
'\uDBFF'
. A high-surrogate is also known as a leading-surrogate.public static final char MIN_LOW_SURROGATE
'\uDC00'
. A low-surrogate is also known as a trailing-surrogate.public static final char MAX_LOW_SURROGATE
'\uDFFF'
. A low-surrogate is also known as a trailing-surrogate.public static final char MIN_SURROGATE
'\uD800'
.public static final char MAX_SURROGATE
'\uDFFF'
.public static final int MIN_SUPPLEMENTARY_CODE_POINT
U+10000
.public static final int MIN_CODE_POINT
U+0000
.public static final int MAX_CODE_POINT
U+10FFFF
.public static final int SIZE
char
value in unsigned binary form, constant 16
.public static final int BYTES
char
value in unsigned binary form.@Deprecated(since="9", forRemoval=true) public Character(char value)
valueOf(char)
is generally a better choice, as it is likely to yield significantly better space and time performance.Character
object that represents the specified char
value.value
- the value to be represented by the Character
object.public Optional<DynamicConstantDesc<Character>> describeConstable()
Optional
containing the nominal descriptor for this instance.describeConstable
in interface Constable
Optional
describing the Character instancepublic static Character valueOf(char c)
Character
instance representing the specified char
value. If a new Character
instance is not required, this method should generally be used in preference to the constructor Character(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.c
- a char value.Character
instance representing c
.public char charValue()
Character
object.char
value represented by this object.public int hashCode()
Character
; equal to the result of invoking charValue()
.public static int hashCode(char value)
char
value; compatible with Character.hashCode()
.value
- The char
for which to return a hash code.char
value.public boolean equals(Object obj)
true
if and only if the argument is not null
and is a Character
object that represents the same char
value as this object.public String toString()
String
object representing this Character
's value. The result is a string of length 1 whose sole component is the primitive char
value represented by this Character
object.public static String toString(char c)
String
object representing the specified char
. The result is a string of length 1 consisting solely of the specified char
.toString(int)
method.c
- the char
to be convertedchar
public static String toString(int codePoint)
String
object representing the specified character (Unicode code point). The result is a string of length 1 or 2, consisting solely of the specified codePoint
.codePoint
- the codePoint
to be convertedcodePoint
IllegalArgumentException
- if the specified codePoint
is not a valid Unicode code point.public static boolean isValidCodePoint(int codePoint)
codePoint
- the Unicode code point to be testedtrue
if the specified code point value is between MIN_CODE_POINT
and MAX_CODE_POINT
inclusive; false
otherwise.public static boolean isBmpCodePoint(int codePoint)
char
.public static boolean isSupplementaryCodePoint(int codePoint)
codePoint
- the character (Unicode code point) to be testedtrue
if the specified code point is between MIN_SUPPLEMENTARY_CODE_POINT
and MAX_CODE_POINT
inclusive; false
otherwise.public static boolean isHighSurrogate(char ch)
char
value is a Unicode high-surrogate code unit (also known as leading-surrogate code unit). Such values do not represent characters by themselves, but are used in the representation of supplementary characters in the UTF-16 encoding.
ch
- the char
value to be tested.true
if the char
value is between MIN_HIGH_SURROGATE
and MAX_HIGH_SURROGATE
inclusive; false
otherwise.public static boolean isLowSurrogate(char ch)
char
value is a Unicode low-surrogate code unit (also known as trailing-surrogate code unit). Such values do not represent characters by themselves, but are used in the representation of supplementary characters in the UTF-16 encoding.
ch
- the char
value to be tested.true
if the char
value is between MIN_LOW_SURROGATE
and MAX_LOW_SURROGATE
inclusive; false
otherwise.public static boolean isSurrogate(char ch)
char
value is a Unicode surrogate code unit. Such values do not represent characters by themselves, but are used in the representation of supplementary characters in the UTF-16 encoding.
A char value is a surrogate code unit if and only if it is either a low-surrogate code unit or a high-surrogate code unit.
ch
- the char
value to be tested.true
if the char
value is between MIN_SURROGATE
and MAX_SURROGATE
inclusive; false
otherwise.public static boolean isSurrogatePair(char high, char low)
char
values is a valid Unicode surrogate pair. This method is equivalent to the expression:
isHighSurrogate(high) && isLowSurrogate(low)
high
- the high-surrogate code value to be testedlow
- the low-surrogate code value to be testedtrue
if the specified high and low-surrogate code values represent a valid surrogate pair; false
otherwise.public static int charCount(int codePoint)
char
values needed to represent the specified character (Unicode code point). If the specified character is equal to or greater than 0x10000, then the method returns 2. Otherwise, the method returns 1. This method doesn't validate the specified character to be a valid Unicode code point. The caller must validate the character value using isValidCodePoint
if necessary.
codePoint
- the character (Unicode code point) to be tested.public static int toCodePoint(char high, char low)
isSurrogatePair
if necessary.high
- the high-surrogate code unitlow
- the low-surrogate code unitpublic static int codePointAt(CharSequence seq, int index)
CharSequence
. If the char
value at the given index in the CharSequence
is in the high-surrogate range, the following index is less than the length of the CharSequence
, and the char
value at the following index is in the low-surrogate range, then the supplementary code point corresponding to this surrogate pair is returned. Otherwise, the char
value at the given index is returned.seq
- a sequence of char
values (Unicode code units)index
- the index to the char
values (Unicode code units) in seq
to be convertedNullPointerException
- if seq
is null.IndexOutOfBoundsException
- if the value index
is negative or not less than seq.length()
.public static int codePointAt(char[] a, int index)
char
array. If the char
value at the given index in the char
array is in the high-surrogate range, the following index is less than the length of the char
array, and the char
value at the following index is in the low-surrogate range, then the supplementary code point corresponding to this surrogate pair is returned. Otherwise, the char
value at the given index is returned.a
- the char
arrayindex
- the index to the char
values (Unicode code units) in the char
array to be convertedNullPointerException
- if a
is null.IndexOutOfBoundsException
- if the value index
is negative or not less than the length of the char
array.public static int codePointAt(char[] a, int index, int limit)
char
array, where only array elements with index
less than limit
can be used. If the char
value at the given index in the char
array is in the high-surrogate range, the following index is less than the limit
, and the char
value at the following index is in the low-surrogate range, then the supplementary code point corresponding to this surrogate pair is returned. Otherwise, the char
value at the given index is returned.a
- the char
arrayindex
- the index to the char
values (Unicode code units) in the char
array to be convertedlimit
- the index after the last array element that can be used in the char
arrayNullPointerException
- if a
is null.IndexOutOfBoundsException
- if the index
argument is negative or not less than the limit
argument, or if the limit
argument is negative or greater than the length of the char
array.public static int codePointBefore(CharSequence seq, int index)
CharSequence
. If the char
value at (index - 1)
in the CharSequence
is in the low-surrogate range, (index - 2)
is not negative, and the char
value at (index - 2)
in the CharSequence
is in the high-surrogate range, then the supplementary code point corresponding to this surrogate pair is returned. Otherwise, the char
value at (index - 1)
is returned.seq
- the CharSequence
instanceindex
- the index following the code point that should be returnedNullPointerException
- if seq
is null.IndexOutOfBoundsException
- if the index
argument is less than 1 or greater than seq.length()
.public static int codePointBefore(char[] a, int index)
char
array. If the char
value at (index - 1)
in the char
array is in the low-surrogate range, (index - 2)
is not negative, and the char
value at (index - 2)
in the char
array is in the high-surrogate range, then the supplementary code point corresponding to this surrogate pair is returned. Otherwise, the char
value at (index - 1)
is returned.a
- the char
arrayindex
- the index following the code point that should be returnedNullPointerException
- if a
is null.IndexOutOfBoundsException
- if the index
argument is less than 1 or greater than the length of the char
arraypublic static int codePointBefore(char[] a, int index, int start)
char
array, where only array elements with index
greater than or equal to start
can be used. If the char
value at (index - 1)
in the char
array is in the low-surrogate range, (index - 2)
is not less than start
, and the char
value at (index - 2)
in the char
array is in the high-surrogate range, then the supplementary code point corresponding to this surrogate pair is returned. Otherwise, the char
value at (index - 1)
is returned.a
- the char
arrayindex
- the index following the code point that should be returnedstart
- the index of the first array element in the char
arrayNullPointerException
- if a
is null.IndexOutOfBoundsException
- if the index
argument is not greater than the start
argument or is greater than the length of the char
array, or if the start
argument is negative or not less than the length of the char
array.public static char highSurrogate(int codePoint)
char
is returned. If isSupplementaryCodePoint(x)
is true
, then isHighSurrogate
(highSurrogate(x))
and toCodePoint
(highSurrogate(x),
lowSurrogate
(x)) == x
are also always true
.
codePoint
- a supplementary character (Unicode code point)public static char lowSurrogate(int codePoint)
char
is returned. If isSupplementaryCodePoint(x)
is true
, then isLowSurrogate
(lowSurrogate(x))
and toCodePoint
(
highSurrogate
(x), lowSurrogate(x)) == x
are also always true
.
codePoint
- a supplementary character (Unicode code point)public static int toChars(int codePoint, char[] dst, int dstIndex)
dst[dstIndex]
, and 1 is returned. If the specified code point is a supplementary character, its surrogate values are stored in dst[dstIndex]
(high-surrogate) and dst[dstIndex+1]
(low-surrogate), and 2 is returned.codePoint
- the character (Unicode code point) to be converted.dst
- an array of char
in which the codePoint
's UTF-16 value is stored.dstIndex
- the start index into the dst
array where the converted value is stored.IllegalArgumentException
- if the specified codePoint
is not a valid Unicode code point.NullPointerException
- if the specified dst
is null.IndexOutOfBoundsException
- if dstIndex
is negative or not less than dst.length
, or if dst
at dstIndex
doesn't have enough array element(s) to store the resulting char
value(s). (If dstIndex
is equal to dst.length-1
and the specified codePoint
is a supplementary character, the high-surrogate value is not stored in dst[dstIndex]
.)public static char[] toChars(int codePoint)
char
array. If the specified code point is a BMP (Basic Multilingual Plane or Plane 0) value, the resulting char
array has the same value as codePoint
. If the specified code point is a supplementary code point, the resulting char
array has the corresponding surrogate pair.codePoint
- a Unicode code pointchar
array having codePoint
's UTF-16 representation.IllegalArgumentException
- if the specified codePoint
is not a valid Unicode code point.public static int codePointCount(CharSequence seq, int beginIndex, int endIndex)
beginIndex
and extends to the char
at index endIndex - 1
. Thus the length (in char
s) of the text range is endIndex-beginIndex
. Unpaired surrogates within the text range count as one code point each.seq
- the char sequencebeginIndex
- the index to the first char
of the text range.endIndex
- the index after the last char
of the text range.NullPointerException
- if seq
is null.IndexOutOfBoundsException
- if the beginIndex
is negative, or endIndex
is larger than the length of the given sequence, or beginIndex
is larger than endIndex
.public static int codePointCount(char[] a, int offset, int count)
char
array argument. The offset
argument is the index of the first char
of the subarray and the count
argument specifies the length of the subarray in char
s. Unpaired surrogates within the subarray count as one code point each.a
- the char
arrayoffset
- the index of the first char
in the given char
arraycount
- the length of the subarray in char
sNullPointerException
- if a
is null.IndexOutOfBoundsException
- if offset
or count
is negative, or if offset +
count
is larger than the length of the given array.public static int offsetByCodePoints(CharSequence seq, int index, int codePointOffset)
index
by codePointOffset
code points. Unpaired surrogates within the text range given by index
and codePointOffset
count as one code point each.seq
- the char sequenceindex
- the index to be offsetcodePointOffset
- the offset in code pointsNullPointerException
- if seq
is null.IndexOutOfBoundsException
- if index
is negative or larger than the length of the char sequence, or if codePointOffset
is positive and the subsequence starting with index
has fewer than codePointOffset
code points, or if codePointOffset
is negative and the subsequence before index
has fewer than the absolute value of codePointOffset
code points.public static int offsetByCodePoints(char[] a, int start, int count, int index, int codePointOffset)
char
subarray that is offset from the given index
by codePointOffset
code points. The start
and count
arguments specify a subarray of the char
array. Unpaired surrogates within the text range given by index
and codePointOffset
count as one code point each.a
- the char
arraystart
- the index of the first char
of the subarraycount
- the length of the subarray in char
sindex
- the index to be offsetcodePointOffset
- the offset in code pointsNullPointerException
- if a
is null.IndexOutOfBoundsException
- if start
or count
is negative, or if start + count
is larger than the length of the given array, or if index
is less than start
or larger then start + count
, or if codePointOffset
is positive and the text range starting with index
and ending with start + count - 1
has fewer than codePointOffset
code points, or if codePointOffset
is negative and the text range starting with start
and ending with index - 1
has fewer than the absolute value of codePointOffset
code points.public static boolean isLowerCase(char ch)
A character is lowercase if its general category type, provided by Character.getType(ch)
, is LOWERCASE_LETTER
, or it has contributory property Other_Lowercase as defined by the Unicode Standard.
The following are examples of lowercase characters:
a b c d e f g h i j k l m n o p q r s t u v w x y z '\u00DF' '\u00E0' '\u00E1' '\u00E2' '\u00E3' '\u00E4' '\u00E5' '\u00E6' '\u00E7' '\u00E8' '\u00E9' '\u00EA' '\u00EB' '\u00EC' '\u00ED' '\u00EE' '\u00EF' '\u00F0' '\u00F1' '\u00F2' '\u00F3' '\u00F4' '\u00F5' '\u00F6' '\u00F8' '\u00F9' '\u00FA' '\u00FB' '\u00FC' '\u00FD' '\u00FE' '\u00FF'
Many other Unicode characters are lowercase too.
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isLowerCase(int)
method.
ch
- the character to be tested.true
if the character is lowercase; false
otherwise.public static boolean isLowerCase(int codePoint)
A character is lowercase if its general category type, provided by getType(codePoint)
, is LOWERCASE_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.
codePoint
- the character (Unicode code point) to be tested.true
if the character is lowercase; false
otherwise.public static boolean isUpperCase(char ch)
A character is uppercase if its general category type, provided by Character.getType(ch)
, is UPPERCASE_LETTER
. or it has contributory property Other_Uppercase as defined by the Unicode Standard.
The following are examples of uppercase characters:
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z '\u00C0' '\u00C1' '\u00C2' '\u00C3' '\u00C4' '\u00C5' '\u00C6' '\u00C7' '\u00C8' '\u00C9' '\u00CA' '\u00CB' '\u00CC' '\u00CD' '\u00CE' '\u00CF' '\u00D0' '\u00D1' '\u00D2' '\u00D3' '\u00D4' '\u00D5' '\u00D6' '\u00D8' '\u00D9' '\u00DA' '\u00DB' '\u00DC' '\u00DD' '\u00DE'
Many other Unicode characters are uppercase too.
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isUpperCase(int)
method.
ch
- the character to be tested.true
if the character is uppercase; false
otherwise.public static boolean isUpperCase(int codePoint)
A character is uppercase if its general category type, provided by getType(codePoint)
, is UPPERCASE_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.
codePoint
- the character (Unicode code point) to be tested.true
if the character is uppercase; false
otherwise.public static boolean isTitleCase(char ch)
A character is a titlecase character if its general category type, provided by Character.getType(ch)
, is TITLECASE_LETTER
.
Some characters look like pairs of Latin letters. For example, there is an uppercase letter that looks like "LJ" and has a corresponding lowercase letter that looks like "lj". A third form, which looks like "Lj", is the appropriate form to use when rendering a word in lowercase with initial capitals, as for a book title.
These are some of the Unicode characters for which this method returns true
:
LATIN CAPITAL LETTER D WITH SMALL LETTER Z WITH CARON
LATIN CAPITAL LETTER L WITH SMALL LETTER J
LATIN CAPITAL LETTER N WITH SMALL LETTER J
LATIN CAPITAL LETTER D WITH SMALL LETTER Z
Many other Unicode characters are titlecase too.
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isTitleCase(int)
method.
ch
- the character to be tested.true
if the character is titlecase; false
otherwise.public static boolean isTitleCase(int codePoint)
A character is a titlecase character if its general category type, provided by getType(codePoint)
, is TITLECASE_LETTER
.
Some characters look like pairs of Latin letters. For example, there is an uppercase letter that looks like "LJ" and has a corresponding lowercase letter that looks like "lj". A third form, which looks like "Lj", is the appropriate form to use when rendering a word in lowercase with initial capitals, as for a book title.
These are some of the Unicode characters for which this method returns true
:
LATIN CAPITAL LETTER D WITH SMALL LETTER Z WITH CARON
LATIN CAPITAL LETTER L WITH SMALL LETTER J
LATIN CAPITAL LETTER N WITH SMALL LETTER J
LATIN CAPITAL LETTER D WITH SMALL LETTER Z
Many other Unicode characters are titlecase too.
codePoint
- the character (Unicode code point) to be tested.true
if the character is titlecase; false
otherwise.public static boolean isDigit(char ch)
A character is a digit if its general category type, provided by Character.getType(ch)
, is DECIMAL_DIGIT_NUMBER
.
Some Unicode character ranges that contain digits:
'\u0030'
through '\u0039'
, ISO-LATIN-1 digits ('0'
through '9'
) '\u0660'
through '\u0669'
, Arabic-Indic digits '\u06F0'
through '\u06F9'
, Extended Arabic-Indic digits '\u0966'
through '\u096F'
, Devanagari digits '\uFF10'
through '\uFF19'
, Fullwidth digits Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isDigit(int)
method.
ch
- the character to be tested.true
if the character is a digit; false
otherwise.public static boolean isDigit(int codePoint)
A character is a digit if its general category type, provided by getType(codePoint)
, is DECIMAL_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 codePoint
- the character (Unicode code point) to be tested.true
if the character is a digit; false
otherwise.public static boolean isDefined(char ch)
A character is defined if at least one of the following is true:
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isDefined(int)
method.
ch
- the character to be testedtrue
if the character has a defined meaning in Unicode; false
otherwise.public static boolean isDefined(int codePoint)
A character is defined if at least one of the following is true:
codePoint
- the character (Unicode code point) to be tested.true
if the character has a defined meaning in Unicode; false
otherwise.public static boolean isLetter(char ch)
A character is considered to be a letter if its general category type, provided by Character.getType(ch)
, is any of the following:
UPPERCASE_LETTER
LOWERCASE_LETTER
TITLECASE_LETTER
MODIFIER_LETTER
OTHER_LETTER
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isLetter(int)
method.
ch
- the character to be tested.true
if the character is a letter; false
otherwise.public static boolean isLetter(int codePoint)
A character is considered to be a letter if its general category type, provided by getType(codePoint)
, is any of the following:
UPPERCASE_LETTER
LOWERCASE_LETTER
TITLECASE_LETTER
MODIFIER_LETTER
OTHER_LETTER
codePoint
- the character (Unicode code point) to be tested.true
if the character is a letter; false
otherwise.public static boolean isLetterOrDigit(char ch)
A character is considered to be a letter or digit if either Character.isLetter(char ch)
or Character.isDigit(char ch)
returns true
for the character.
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isLetterOrDigit(int)
method.
ch
- the character to be tested.true
if the character is a letter or digit; false
otherwise.public static boolean isLetterOrDigit(int codePoint)
A character is considered to be a letter or digit if either isLetter(codePoint)
or isDigit(codePoint)
returns true
for the character.
codePoint
- the character (Unicode code point) to be tested.true
if the character is a letter or digit; false
otherwise.@Deprecated(since="1.1") public static boolean isJavaLetter(char ch)
A character may start a Java identifier if and only if one of the following conditions is true:
isLetter(ch)
returns true
getType(ch)
returns LETTER_NUMBER
ch
is a currency symbol (such as '$'
) ch
is a connecting punctuation character (such as '_'
). ch
- the character to be tested.true
if the character may start a Java identifier; false
otherwise.@Deprecated(since="1.1") public static boolean isJavaLetterOrDigit(char ch)
A character may be part of a Java identifier if and only if one of the following conditions is true:
'$'
) '_'
) isIdentifierIgnorable
returns true
for the character. ch
- the character to be tested.true
if the character may be part of a Java identifier; false
otherwise.public static boolean isAlphabetic(int codePoint)
A character is considered to be alphabetic if its general category type, provided by getType(codePoint)
, is any of the following:
UPPERCASE_LETTER
LOWERCASE_LETTER
TITLECASE_LETTER
MODIFIER_LETTER
OTHER_LETTER
LETTER_NUMBER
codePoint
- the character (Unicode code point) to be tested.true
if the character is a Unicode alphabet character, false
otherwise.public static boolean isIdeographic(int codePoint)
codePoint
- the character (Unicode code point) to be tested.true
if the character is a Unicode ideograph character, false
otherwise.public static boolean isJavaIdentifierStart(char ch)
A character may start a Java identifier if and only if one of the following conditions is true:
isLetter(ch)
returns true
getType(ch)
returns LETTER_NUMBER
ch
is a currency symbol (such as '$'
) ch
is a connecting punctuation character (such as '_'
). Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isJavaIdentifierStart(int)
method.
ch
- the character to be tested.true
if the character may start a Java identifier; false
otherwise.public static boolean isJavaIdentifierStart(int codePoint)
A character may start a Java identifier if and only if one of the following conditions is true:
isLetter(codePoint)
returns true
getType(codePoint)
returns LETTER_NUMBER
'$'
) '_'
). codePoint
- the character (Unicode code point) to be tested.true
if the character may start a Java identifier; false
otherwise.public static boolean isJavaIdentifierPart(char ch)
A character may be part of a Java identifier if any of the following conditions are true:
'$'
) '_'
) isIdentifierIgnorable
returns true
for the character Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isJavaIdentifierPart(int)
method.
ch
- the character to be tested.true
if the character may be part of a Java identifier; false
otherwise.public static boolean isJavaIdentifierPart(int codePoint)
A character may be part of a Java identifier if any of the following conditions are true:
'$'
) '_'
) isIdentifierIgnorable(codePoint)
returns true
for the code point codePoint
- the character (Unicode code point) to be tested.true
if the character may be part of a Java identifier; false
otherwise.public static boolean isUnicodeIdentifierStart(char ch)
A character may start a Unicode identifier if and only if one of the following conditions is true:
isLetter(ch)
returns true
getType(ch)
returns LETTER_NUMBER
. Other_ID_Start
character. This method conforms to UAX31-R1: Default Identifiers requirement of the Unicode Standard, with the following profile of UAX31:
Start := ID_Start + 'VERTICAL TILDE' (U+2E2F)
'VERTICAL TILDE'
is added to Start
for backward compatibility. Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isUnicodeIdentifierStart(int)
method.
ch
- the character to be tested.true
if the character may start a Unicode identifier; false
otherwise.public static boolean isUnicodeIdentifierStart(int codePoint)
A character may start a Unicode identifier if and only if one of the following conditions is true:
isLetter(codePoint)
returns true
getType(codePoint)
returns LETTER_NUMBER
. Other_ID_Start
character. This method conforms to UAX31-R1: Default Identifiers requirement of the Unicode Standard, with the following profile of UAX31:
Start := ID_Start + 'VERTICAL TILDE' (U+2E2F)
'VERTICAL TILDE'
is added to Start
for backward compatibility.codePoint
- the character (Unicode code point) to be tested.true
if the character may start a Unicode identifier; false
otherwise.public static boolean isUnicodeIdentifierPart(char ch)
A character may be part of a Unicode identifier if and only if one of the following statements is true:
'_'
) isIdentifierIgnorable
returns true
for this character. Other_ID_Start
character. Other_ID_Continue
character. This method conforms to UAX31-R1: Default Identifiers requirement of the Unicode Standard, with the following profile of UAX31:
Continue := Start + ID_Continue + ignorable Medial := empty ignorable := isIdentifierIgnorable(char) returns true for the character
ignorable
is added to Continue
for backward compatibility. Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isUnicodeIdentifierPart(int)
method.
ch
- the character to be tested.true
if the character may be part of a Unicode identifier; false
otherwise.public static boolean isUnicodeIdentifierPart(int codePoint)
A character may be part of a Unicode identifier if and only if one of the following statements is true:
'_'
) isIdentifierIgnorable
returns true
for this character. Other_ID_Start
character. Other_ID_Continue
character. This method conforms to UAX31-R1: Default Identifiers requirement of the Unicode Standard, with the following profile of UAX31:
Continue := Start + ID_Continue + ignorable Medial := empty ignorable := isIdentifierIgnorable(int) returns true for the character
ignorable
is added to Continue
for backward compatibility.codePoint
- the character (Unicode code point) to be tested.true
if the character may be part of a Unicode identifier; false
otherwise.public static boolean isIdentifierIgnorable(char ch)
The following Unicode characters are ignorable in a Java identifier or a Unicode identifier:
'\u0000'
through '\u0008'
'\u000E'
through '\u001B'
'\u007F'
through '\u009F'
FORMAT
general category value Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isIdentifierIgnorable(int)
method.
ch
- the character to be tested.true
if the character is an ignorable control character that may be part of a Java or Unicode identifier; false
otherwise.public static boolean isIdentifierIgnorable(int codePoint)
The following Unicode characters are ignorable in a Java identifier or a Unicode identifier:
'\u0000'
through '\u0008'
'\u000E'
through '\u001B'
'\u007F'
through '\u009F'
FORMAT
general category value codePoint
- the character (Unicode code point) to be tested.true
if the character is an ignorable control character that may be part of a Java or Unicode identifier; false
otherwise.public static boolean isEmoji(int codePoint)
A character is considered to be an Emoji if and only if it has the Emoji
property, defined in Unicode Emoji (Technical Standard #51).
codePoint
- the character (Unicode code point) to be tested.true
if the character is an Emoji; false
otherwise.public static boolean isEmojiPresentation(int codePoint)
A character is considered to have the Emoji Presentation property if and only if it has the Emoji_Presentation
property, defined in Unicode Emoji (Technical Standard #51).
codePoint
- the character (Unicode code point) to be tested.true
if the character has the Emoji Presentation property; false
otherwise.public static boolean isEmojiModifier(int codePoint)
A character is considered to be an Emoji Modifier if and only if it has the Emoji_Modifier
property, defined in Unicode Emoji (Technical Standard #51).
codePoint
- the character (Unicode code point) to be tested.true
if the character is an Emoji Modifier; false
otherwise.public static boolean isEmojiModifierBase(int codePoint)
A character is considered to be an Emoji Modifier Base if and only if it has the Emoji_Modifier_Base
property, defined in Unicode Emoji (Technical Standard #51).
codePoint
- the character (Unicode code point) to be tested.true
if the character is an Emoji Modifier Base; false
otherwise.public static boolean isEmojiComponent(int codePoint)
A character is considered to be an Emoji Component if and only if it has the Emoji_Component
property, defined in Unicode Emoji (Technical Standard #51).
codePoint
- the character (Unicode code point) to be tested.true
if the character is an Emoji Component; false
otherwise.public static boolean isExtendedPictographic(int codePoint)
A character is considered to be an Extended Pictographic if and only if it has the Extended_Pictographic
property, defined in Unicode Emoji (Technical Standard #51).
codePoint
- the character (Unicode code point) to be tested.true
if the character is an Extended Pictographic; false
otherwise.public static char toLowerCase(char ch)
Note that Character.isLowerCase(Character.toLowerCase(ch))
does not always return true
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 over Character
case mapping methods. String
case mapping methods can perform locale-sensitive mappings, context-sensitive mappings, and 1:M character mappings, whereas the Character
case mapping methods cannot.
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the toLowerCase(int)
method.
ch
- the character to be converted.public static int toLowerCase(int codePoint)
Note that Character.isLowerCase(Character.toLowerCase(codePoint))
does not always return true
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 over Character
case mapping methods. String
case mapping methods can perform locale-sensitive mappings, context-sensitive mappings, and 1:M character mappings, whereas the Character
case mapping methods cannot.
codePoint
- the character (Unicode code point) to be converted.public static char toUpperCase(char ch)
Note that Character.isUpperCase(Character.toUpperCase(ch))
does not always return true
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 over Character
case mapping methods. String
case mapping methods can perform locale-sensitive mappings, context-sensitive mappings, and 1:M character mappings, whereas the Character
case mapping methods cannot.
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the toUpperCase(int)
method.
ch
- the character to be converted.public static int toUpperCase(int codePoint)
Note that Character.isUpperCase(Character.toUpperCase(codePoint))
does not always return true
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 over Character
case mapping methods. String
case mapping methods can perform locale-sensitive mappings, context-sensitive mappings, and 1:M character mappings, whereas the Character
case mapping methods cannot.
codePoint
- the character (Unicode code point) to be converted.public static char toTitleCase(char ch)
char
argument is already a titlecase char
, the same char
value will be returned. Note that Character.isTitleCase(Character.toTitleCase(ch))
does not always return true
for some ranges of characters.
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the toTitleCase(int)
method.
ch
- the character to be converted.public static int toTitleCase(int codePoint)
Note that Character.isTitleCase(Character.toTitleCase(codePoint))
does not always return true
for some ranges of characters.
codePoint
- the character (Unicode code point) to be converted.public static int digit(char ch, int radix)
ch
in the specified radix. If the radix is not in the range MIN_RADIX
≤ radix
≤ MAX_RADIX
or if the value of ch
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:
isDigit
is true
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. 'A'
through 'Z'
and its code is less than radix + 'A' - 10
. In this case, ch - 'A' + 10
is returned. 'a'
through 'z'
and its code is less than radix + 'a' - 10
. In this case, ch - 'a' + 10
is returned. '\uFF21'
) through Z ('\uFF3A'
) and its code is less than radix + '\uFF21' - 10
. In this case, ch - '\uFF21' + 10
is returned. '\uFF41'
) through z ('\uFF5A'
) and its code is less than radix + '\uFF41' - 10
. In this case, ch - '\uFF41' + 10
is returned. Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the digit(int, int)
method.
ch
- the character to be converted.radix
- the radix.public static int digit(int codePoint, int radix)
If the radix is not in the range MIN_RADIX
≤ radix
≤ MAX_RADIX
or if the character is not a valid digit in the specified radix, -1
is returned. A character is a valid digit if at least one of the following is true:
isDigit(codePoint)
is true
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. 'A'
through 'Z'
and its code is less than radix + 'A' - 10
. In this case, codePoint - 'A' + 10
is returned. 'a'
through 'z'
and its code is less than radix + 'a' - 10
. In this case, codePoint - 'a' + 10
is returned. '\uFF21'
) through Z ('\uFF3A'
) and its code is less than radix + '\uFF21' - 10
. In this case, codePoint - '\uFF21' + 10
is returned. '\uFF41'
) through z ('\uFF5A'
) and its code is less than radix + '\uFF41'- 10
. In this case, codePoint - '\uFF41' + 10
is returned. codePoint
- the character (Unicode code point) to be converted.radix
- the radix.public static int getNumericValue(char ch)
int
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 these char
values.
If the character does not have a numeric value, then -1 is returned. If the character has a numeric value that cannot be represented as a nonnegative integer (for example, a fractional value), then -2 is returned.
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the getNumericValue(int)
method.
ch
- the character to be converted.int
value; -2 if the character has a numeric value but the value can not be represented as a nonnegative int
value; -1 if the character has no numeric value.public static int getNumericValue(int codePoint)
int
value that the specified character (Unicode code point) 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 these char
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.
codePoint
- the character (Unicode code point) to be converted.int
value; -2 if the character has a numeric value but the value can not be represented as a nonnegative int
value; -1 if the character has no numeric value.@Deprecated(since="1.1") public static boolean isSpace(char ch)
true
for the following five characters only: Character | Code | Name |
---|---|---|
'\t' | U+0009 | HORIZONTAL TABULATION |
'\n' | U+000A | NEW LINE |
'\f' | U+000C | FORM FEED |
'\r' | U+000D | CARRIAGE RETURN |
' ' | U+0020 | SPACE |
ch
- the character to be tested.true
if the character is ISO-LATIN-1 white space; false
otherwise.public static boolean isSpaceChar(char ch)
SPACE_SEPARATOR
LINE_SEPARATOR
PARAGRAPH_SEPARATOR
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isSpaceChar(int)
method.
ch
- the character to be tested.true
if the character is a space character; false
otherwise.public static boolean isSpaceChar(int codePoint)
codePoint
- the character (Unicode code point) to be tested.true
if the character is a space character; false
otherwise.public static boolean isWhitespace(char ch)
SPACE_SEPARATOR
, LINE_SEPARATOR
, or PARAGRAPH_SEPARATOR
) but is not also a non-breaking space ('\u00A0'
, '\u2007'
, '\u202F'
). '\t'
, U+0009 HORIZONTAL TABULATION. '\n'
, U+000A LINE FEED. '\u000B'
, U+000B VERTICAL TABULATION. '\f'
, U+000C FORM FEED. '\r'
, U+000D CARRIAGE RETURN. '\u001C'
, U+001C FILE SEPARATOR. '\u001D'
, U+001D GROUP SEPARATOR. '\u001E'
, U+001E RECORD SEPARATOR. '\u001F'
, U+001F UNIT SEPARATOR. Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isWhitespace(int)
method.
ch
- the character to be tested.true
if the character is a Java whitespace character; false
otherwise.public static boolean isWhitespace(int codePoint)
SPACE_SEPARATOR
, LINE_SEPARATOR
, or PARAGRAPH_SEPARATOR
) but is not also a non-breaking space ('\u00A0'
, '\u2007'
, '\u202F'
). '\t'
, U+0009 HORIZONTAL TABULATION. '\n'
, U+000A LINE FEED. '\u000B'
, U+000B VERTICAL TABULATION. '\f'
, U+000C FORM FEED. '\r'
, U+000D CARRIAGE RETURN. '\u001C'
, U+001C FILE SEPARATOR. '\u001D'
, U+001D GROUP SEPARATOR. '\u001E'
, U+001E RECORD SEPARATOR. '\u001F'
, U+001F UNIT SEPARATOR. codePoint
- the character (Unicode code point) to be tested.true
if the character is a Java whitespace character; false
otherwise.public static boolean isISOControl(char ch)
'\u0000'
through '\u001F'
or in the range '\u007F'
through '\u009F'
. Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isISOControl(int)
method.
ch
- the character to be tested.true
if the character is an ISO control character; false
otherwise.public static boolean isISOControl(int codePoint)
'\u0000'
through '\u001F'
or in the range '\u007F'
through '\u009F'
.codePoint
- the character (Unicode code point) to be tested.true
if the character is an ISO control character; false
otherwise.public static int getType(char ch)
Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the getType(int)
method.
ch
- the character to be tested.int
representing the character's general category.public static int getType(int codePoint)
codePoint
- the character (Unicode code point) to be tested.int
representing the character's general category.public static char forDigit(int digit, int radix)
radix
is not a valid radix, or the value of digit
is not a valid digit in the specified radix, the null character ('\u0000'
) is returned. The radix
argument is valid if it is greater than or equal to MIN_RADIX
and less than or equal to MAX_RADIX
. The digit
argument is valid if 0 <= digit < radix
.
If the digit is less than 10, then '0' + digit
is returned. Otherwise, the value 'a' + digit - 10
is returned.
digit
- the number to convert to a character.radix
- the radix.char
representation of the specified digit in the specified radix.public static byte getDirectionality(char ch)
char
values is DIRECTIONALITY_UNDEFINED
. Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the getDirectionality(int)
method.
ch
- char
for which the directionality property is requested.char
value.public static byte getDirectionality(int codePoint)
DIRECTIONALITY_UNDEFINED
.codePoint
- the character (Unicode code point) for which the directionality property is requested.public static boolean isMirrored(char ch)
'\u0028'
LEFT PARENTHESIS is semantically defined to be an opening parenthesis. This will appear as a "(" in text that is left-to-right but as a ")" in text that is right-to-left. Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the isMirrored(int)
method.
ch
- char
for which the mirrored property is requestedtrue
if the char is mirrored, false
if the char
is not mirrored or is not defined.public static boolean isMirrored(int codePoint)
'\u0028'
LEFT PARENTHESIS is semantically defined to be an opening parenthesis. This will appear as a "(" in text that is left-to-right but as a ")" in text that is right-to-left.codePoint
- the character (Unicode code point) to be tested.true
if the character is mirrored, false
if the character is not mirrored or is not defined.public int compareTo(Character anotherCharacter)
Character
objects numerically.compareTo
in interface Comparable<Character>
anotherCharacter
- the Character
to be compared.0
if the argument Character
is equal to this Character
; a value less than 0
if this Character
is numerically less than the Character
argument; and a value greater than 0
if this Character
is numerically greater than the Character
argument (unsigned comparison). Note that this is strictly a numerical comparison; it is not locale-dependent.public static int compare(char x, char y)
char
values numerically. The value returned is identical to what would be returned by: Character.valueOf(x).compareTo(Character.valueOf(y))
x
- the first char
to comparey
- the second char
to compare0
if x == y
; a value less than 0
if x < y
; and a value greater than 0
if x > y
public static char reverseBytes(char ch)
char
value.ch
- The char
of which to reverse the byte order.char
value.public static String getName(int codePoint)
codePoint
, or null if the code point is unassigned
. If the specified character is not assigned a name by the UnicodeData file (part of the Unicode Character Database maintained by the Unicode Consortium), the returned name is the same as the result of the expression:
Character.UnicodeBlock.of(codePoint).toString().replace('_', ' ')
+ " "
+ Integer.toHexString(codePoint).toUpperCase(Locale.ROOT);
For the codePoint
s in the UnicodeData file, the name returned by this method follows the naming scheme in the "Unicode Name Property" section of the Unicode Standard. For other code points, such as Hangul/Ideographs, The name generation rule above differs from the one defined in the Unicode Standard.codePoint
- the character (Unicode code point)IllegalArgumentException
- if the specified codePoint
is not a valid Unicode code point.public static int codePointOf(String name)
If a character is not assigned a name by the UnicodeData file (part of the Unicode Character Database maintained by the Unicode Consortium), its name is defined as the result of the expression:
Character.UnicodeBlock.of(codePoint).toString().replace('_', ' ')
+ " "
+ Integer.toHexString(codePoint).toUpperCase(Locale.ROOT);
The name
matching is case insensitive, with any leading and trailing whitespace character removed. For the code points in the UnicodeData file, this method recognizes the name which conforms to the name defined in the "Unicode Name Property" section in the Unicode Standard. For other code points, this method recognizes the name generated with getName(int)
method.
name
- the character nameIllegalArgumentException
- if the specified name
is not a valid character name.NullPointerException
- if name
is null
© 1993, 2023, Oracle and/or its affiliates. All rights reserved.
Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.
https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/lang/Character.html