java.lang.Object | |
↳ | java.lang.Character |
The Character
class wraps a value of the primitive
type char
in an object. An object of type
Character
contains a single field whose type is
char
.
In addition, this class provides several methods for determining a character's category (lowercase letter, digit, etc.) and for converting characters from uppercase to lowercase and vice versa.
Character information is based on the Unicode Standard, version 4.0.
The methods and data of class Character
are defined by
the information in the UnicodeData file that is part of the
Unicode Character Database maintained by the Unicode
Consortium. This file specifies various properties including name
and general category for every defined Unicode code point or
character range.
The file and its description are available from the Unicode Consortium at:
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
2 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.
Nested Classes | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Character.Subset | Instances of this class represent particular subsets of the Unicode character set. | ||||||||||
Character.UnicodeBlock | A family of character subsets representing the character blocks in the Unicode specification. |
Constants | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
byte | COMBINING_SPACING_MARK | General category "Mc" in the Unicode specification. | |||||||||
byte | CONNECTOR_PUNCTUATION | General category "Pc" in the Unicode specification. | |||||||||
byte | CONTROL | General category "Cc" in the Unicode specification. | |||||||||
byte | CURRENCY_SYMBOL | General category "Sc" in the Unicode specification. | |||||||||
byte | DASH_PUNCTUATION | General category "Pd" in the Unicode specification. | |||||||||
byte | DECIMAL_DIGIT_NUMBER | General category "Nd" in the Unicode specification. | |||||||||
byte | DIRECTIONALITY_ARABIC_NUMBER | Weak bidirectional character type "AN" in the Unicode specification. | |||||||||
byte | DIRECTIONALITY_BOUNDARY_NEUTRAL | Weak bidirectional character type "BN" in the Unicode specification. | |||||||||
byte | DIRECTIONALITY_COMMON_NUMBER_SEPARATOR | Weak bidirectional character type "CS" in the Unicode specification. | |||||||||
byte | DIRECTIONALITY_EUROPEAN_NUMBER | Weak bidirectional character type "EN" in the Unicode specification. | |||||||||
byte | DIRECTIONALITY_EUROPEAN_NUMBER_SEPARATOR | Weak bidirectional character type "ES" in the Unicode specification. | |||||||||
byte | DIRECTIONALITY_EUROPEAN_NUMBER_TERMINATOR | Weak bidirectional character type "ET" in the Unicode specification. | |||||||||
byte | DIRECTIONALITY_LEFT_TO_RIGHT | Strong bidirectional character type "L" in the Unicode specification. | |||||||||
byte | DIRECTIONALITY_LEFT_TO_RIGHT_EMBEDDING | Strong bidirectional character type "LRE" in the Unicode specification. | |||||||||
byte | DIRECTIONALITY_LEFT_TO_RIGHT_OVERRIDE | Strong bidirectional character type "LRO" in the Unicode specification. | |||||||||
byte | DIRECTIONALITY_NONSPACING_MARK | Weak bidirectional character type "NSM" in the Unicode specification. | |||||||||
byte | DIRECTIONALITY_OTHER_NEUTRALS | Neutral bidirectional character type "ON" in the Unicode specification. | |||||||||
byte | DIRECTIONALITY_PARAGRAPH_SEPARATOR | Neutral bidirectional character type "B" in the Unicode specification. | |||||||||
byte | DIRECTIONALITY_POP_DIRECTIONAL_FORMAT | Weak bidirectional character type "PDF" in the Unicode specification. | |||||||||
byte | DIRECTIONALITY_RIGHT_TO_LEFT | Strong bidirectional character type "R" in the Unicode specification. | |||||||||
byte | DIRECTIONALITY_RIGHT_TO_LEFT_ARABIC | Strong bidirectional character type "AL" in the Unicode specification. | |||||||||
byte | DIRECTIONALITY_RIGHT_TO_LEFT_EMBEDDING | Strong bidirectional character type "RLE" in the Unicode specification. | |||||||||
byte | DIRECTIONALITY_RIGHT_TO_LEFT_OVERRIDE | Strong bidirectional character type "RLO" in the Unicode specification. | |||||||||
byte | DIRECTIONALITY_SEGMENT_SEPARATOR | Neutral bidirectional character type "S" in the Unicode specification. | |||||||||
byte | DIRECTIONALITY_UNDEFINED | Undefined bidirectional character type. | |||||||||
byte | DIRECTIONALITY_WHITESPACE | Neutral bidirectional character type "WS" in the Unicode specification. | |||||||||
byte | ENCLOSING_MARK | General category "Me" in the Unicode specification. | |||||||||
byte | END_PUNCTUATION | General category "Pe" in the Unicode specification. | |||||||||
byte | FINAL_QUOTE_PUNCTUATION | General category "Pf" in the Unicode specification. | |||||||||
byte | FORMAT | General category "Cf" in the Unicode specification. | |||||||||
byte | INITIAL_QUOTE_PUNCTUATION | General category "Pi" in the Unicode specification. | |||||||||
byte | LETTER_NUMBER | General category "Nl" in the Unicode specification. | |||||||||
byte | LINE_SEPARATOR | General category "Zl" in the Unicode specification. | |||||||||
byte | LOWERCASE_LETTER | General category "Ll" in the Unicode specification. | |||||||||
byte | MATH_SYMBOL | General category "Sm" in the Unicode specification. | |||||||||
int | MAX_CODE_POINT | The maximum value of a Unicode code point. | |||||||||
char | MAX_HIGH_SURROGATE | The maximum value of a Unicode high-surrogate code unit in the UTF-16 encoding. | |||||||||
char | MAX_LOW_SURROGATE | The maximum value of a Unicode low-surrogate code unit in the UTF-16 encoding. | |||||||||
int | MAX_RADIX | The maximum radix available for conversion to and from strings. | |||||||||
char | MAX_SURROGATE | The maximum value of a Unicode surrogate code unit in the UTF-16 encoding. | |||||||||
char | MAX_VALUE | The constant value of this field is the largest value of type
char , '\uFFFF' . |
|||||||||
int | MIN_CODE_POINT | The minimum value of a Unicode code point. | |||||||||
char | MIN_HIGH_SURROGATE | The minimum value of a Unicode high-surrogate code unit in the UTF-16 encoding. | |||||||||
char | MIN_LOW_SURROGATE | The minimum value of a Unicode low-surrogate code unit in the UTF-16 encoding. | |||||||||
int | MIN_RADIX | The minimum radix available for conversion to and from strings. | |||||||||
int | MIN_SUPPLEMENTARY_CODE_POINT | The minimum value of a supplementary code point. | |||||||||
char | MIN_SURROGATE | The minimum value of a Unicode surrogate code unit in the UTF-16 encoding. | |||||||||
char | MIN_VALUE | The constant value of this field is the smallest value of type
char , '\u0000' . |
|||||||||
byte | MODIFIER_LETTER | General category "Lm" in the Unicode specification. | |||||||||
byte | MODIFIER_SYMBOL | General category "Sk" in the Unicode specification. | |||||||||
byte | NON_SPACING_MARK | General category "Mn" in the Unicode specification. | |||||||||
byte | OTHER_LETTER | General category "Lo" in the Unicode specification. | |||||||||
byte | OTHER_NUMBER | General category "No" in the Unicode specification. | |||||||||
byte | OTHER_PUNCTUATION | General category "Po" in the Unicode specification. | |||||||||
byte | OTHER_SYMBOL | General category "So" in the Unicode specification. | |||||||||
byte | PARAGRAPH_SEPARATOR | General category "Zp" in the Unicode specification. | |||||||||
byte | PRIVATE_USE | General category "Co" in the Unicode specification. | |||||||||
int | SIZE | The number of bits used to represent a char value in unsigned binary form. | |||||||||
byte | SPACE_SEPARATOR | General category "Zs" in the Unicode specification. | |||||||||
byte | START_PUNCTUATION | General category "Ps" in the Unicode specification. | |||||||||
byte | SURROGATE | General category "Cs" in the Unicode specification. | |||||||||
byte | TITLECASE_LETTER | General category "Lt" in the Unicode specification. | |||||||||
byte | UNASSIGNED | General category "Cn" in the Unicode specification. | |||||||||
byte | UPPERCASE_LETTER | General category "Lu" in the Unicode specification. |
Fields | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
TYPE | The Class instance representing the primitive type
char . |
Public Constructors | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Constructs a newly allocated
Character object that
represents the specified char value. |
Public Methods | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Determines the number of
char values needed to
represent the specified character (Unicode code point). | |||||||||||
Returns the value of this
Character object. | |||||||||||
Returns the code point at the given index of the
char array. | |||||||||||
Returns the code point at the given index of the
char array, where only array elements with
index less than limit can be used. | |||||||||||
Returns the code point at the given index of the
CharSequence . | |||||||||||
Returns the code point preceding the given index of the
CharSequence . | |||||||||||
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. | |||||||||||
Returns the code point preceding the given index of the
char array. | |||||||||||
Returns the number of Unicode code points in the text range of
the specified char sequence.
| |||||||||||
Returns the number of Unicode code points in a subarray of the
char array argument. | |||||||||||
Compares two
Character objects numerically. | |||||||||||
Returns the numeric value of the character
ch in the
specified radix. | |||||||||||
Returns the numeric value of the specified character (Unicode
code point) in the specified radix.
| |||||||||||
Compares this object against the specified object.
| |||||||||||
Determines the character representation for a specific digit in
the specified radix.
| |||||||||||
Returns the Unicode directionality property for the given
character (Unicode code point).
| |||||||||||
Returns the Unicode directionality property for the given
character.
| |||||||||||
Returns the
int value that the specified
character (Unicode code point) represents. | |||||||||||
Returns the
int value that the specified Unicode
character represents. | |||||||||||
Returns a value indicating a character's general category.
| |||||||||||
Returns a value indicating a character's general category.
| |||||||||||
Returns a hash code for this
Character . | |||||||||||
Determines if a character (Unicode code point) is defined in Unicode.
| |||||||||||
Determines if a character is defined in Unicode.
| |||||||||||
Determines if the specified character is a digit.
| |||||||||||
Determines if the specified character (Unicode code point) is a digit.
| |||||||||||
Determines if the given
char value is a
high-surrogate code unit (also known as leading-surrogate
code unit). | |||||||||||
Determines if the specified character is an ISO control
character.
| |||||||||||
Determines if the referenced character (Unicode code point) is an ISO control
character.
| |||||||||||
Determines if the specified character should be regarded as
an ignorable character in a Java identifier or a Unicode identifier.
| |||||||||||
Determines if the specified character (Unicode code point) should be regarded as
an ignorable character in a Java identifier or a Unicode identifier.
| |||||||||||
Determines if the character (Unicode code point) may be part of a Java
identifier as other than the first character.
| |||||||||||
Determines if the specified character may be part of a Java
identifier as other than the first character.
| |||||||||||
Determines if the specified character is
permissible as the first character in a Java identifier.
| |||||||||||
Determines if the character (Unicode code point) is
permissible as the first character in a Java identifier.
| |||||||||||
This method is deprecated.
Replaced by isJavaIdentifierStart(char).
| |||||||||||
This method is deprecated.
Replaced by isJavaIdentifierPart(char).
| |||||||||||
Determines if the specified character is a letter.
| |||||||||||
Determines if the specified character (Unicode code point) is a letter.
| |||||||||||
Determines if the specified character is a letter or digit.
| |||||||||||
Determines if the specified character (Unicode code point) is a letter or digit.
| |||||||||||
Determines if the given
char value is a
low-surrogate code unit (also known as trailing-surrogate code
unit). | |||||||||||
Determines if the specified character (Unicode code point) is a
lowercase character.
| |||||||||||
Determines if the specified character is a lowercase character.
| |||||||||||
Determines whether the character is mirrored according to the
Unicode specification.
| |||||||||||
Determines whether the specified character (Unicode code point)
is mirrored according to the Unicode specification.
| |||||||||||
This method is deprecated.
Replaced by isWhitespace(char).
| |||||||||||
Determines if the specified character is a Unicode space character.
| |||||||||||
Determines if the specified character (Unicode code point) is a
Unicode space character.
| |||||||||||
Determines whether the specified character (Unicode code point)
is in the supplementary character range.
| |||||||||||
Determines whether the specified pair of
char
values is a valid surrogate pair. | |||||||||||
Determines if the specified character (Unicode code point) is a titlecase character.
| |||||||||||
Determines if the specified character is a titlecase character.
| |||||||||||
Determines if the specified character (Unicode code point) may be part of a Unicode
identifier as other than the first character.
| |||||||||||
Determines if the specified character may be part of a Unicode
identifier as other than the first character.
| |||||||||||
Determines if the specified character is permissible as the
first character in a Unicode identifier.
| |||||||||||
Determines if the specified character (Unicode code point) is permissible as the
first character in a Unicode identifier.
| |||||||||||
Determines if the specified character (Unicode code point) is an uppercase character.
| |||||||||||
Determines if the specified character is an uppercase character.
| |||||||||||
Determines whether the specified code point is a valid Unicode
code point value in the range of
0x0000 to
0x10FFFF inclusive. | |||||||||||
Determines if the specified character is white space according to Java.
| |||||||||||
Determines if the specified character (Unicode code point) is
white space according to Java.
| |||||||||||
Returns the index within the given char sequence that is offset
from the given
index by codePointOffset
code points. | |||||||||||
Returns the index within the given
char subarray
that is offset from the given index by
codePointOffset code points. | |||||||||||
Returns the value obtained by reversing the order of the bytes in the
specified char value.
| |||||||||||
Converts the specified character (Unicode code point) to its
UTF-16 representation stored in a
char array. | |||||||||||
Converts the specified character (Unicode code point) to its
UTF-16 representation.
| |||||||||||
Converts the specified surrogate pair to its supplementary code
point value.
| |||||||||||
Converts the character argument to lowercase using case
mapping information from the UnicodeData file.
| |||||||||||
Converts the character (Unicode code point) argument to
lowercase using case mapping information from the UnicodeData
file.
| |||||||||||
Returns a
String object representing the
specified char . | |||||||||||
Returns a
String object representing this
Character 's value. | |||||||||||
Converts the character argument to titlecase using case mapping
information from the UnicodeData file.
| |||||||||||
Converts the character (Unicode code point) argument to titlecase using case mapping
information from the UnicodeData file.
| |||||||||||
Converts the character argument to uppercase using case mapping
information from the UnicodeData file.
| |||||||||||
Converts the character (Unicode code point) argument to
uppercase using case mapping information from the UnicodeData
file.
| |||||||||||
Returns a Character instance representing the specified
char value.
|
[Expand]
Inherited Methods | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
![]() | |||||||||||
![]() |
General category "Mc" in the Unicode specification.
General category "Pc" in the Unicode specification.
General category "Cc" in the Unicode specification.
General category "Sc" in the Unicode specification.
General category "Pd" in the Unicode specification.
General category "Nd" in the Unicode specification.
Weak bidirectional character type "AN" in the Unicode specification.
Weak bidirectional character type "BN" in the Unicode specification.
Weak bidirectional character type "CS" in the Unicode specification.
Weak bidirectional character type "EN" in the Unicode specification.
Weak bidirectional character type "ES" in the Unicode specification.
Weak bidirectional character type "ET" in the Unicode specification.
Strong bidirectional character type "L" in the Unicode specification.
Strong bidirectional character type "LRE" in the Unicode specification.
Strong bidirectional character type "LRO" in the Unicode specification.
Weak bidirectional character type "NSM" in the Unicode specification.
Neutral bidirectional character type "ON" in the Unicode specification.
Neutral bidirectional character type "B" in the Unicode specification.
Weak bidirectional character type "PDF" in the Unicode specification.
Strong bidirectional character type "R" in the Unicode specification.
Strong bidirectional character type "AL" in the Unicode specification.
Strong bidirectional character type "RLE" in the Unicode specification.
Strong bidirectional character type "RLO" in the Unicode specification.
Neutral bidirectional character type "S" in the Unicode specification.
Undefined bidirectional character type. Undefined char
values have undefined directionality in the Unicode specification.
Neutral bidirectional character type "WS" in the Unicode specification.
General category "Me" in the Unicode specification.
General category "Pe" in the Unicode specification.
General category "Pf" in the Unicode specification.
General category "Cf" in the Unicode specification.
General category "Pi" in the Unicode specification.
General category "Nl" in the Unicode specification.
General category "Zl" in the Unicode specification.
General category "Ll" in the Unicode specification.
General category "Sm" in the Unicode specification.
The maximum value of a Unicode code point.
The maximum value of a Unicode high-surrogate code unit in the UTF-16 encoding. A high-surrogate is also known as a leading-surrogate.
The maximum value of a Unicode low-surrogate code unit in the UTF-16 encoding. A low-surrogate is also known as a trailing-surrogate.
The maximum radix available for conversion to and from strings.
The constant value of this field is the largest value permitted
for the radix argument in radix-conversion methods such as the
digit
method, the forDigit
method, and the toString
method of class
Integer
.
The maximum value of a Unicode surrogate code unit in the UTF-16 encoding.
The constant value of this field is the largest value of type
char
, '\uFFFF'
.
The minimum value of a Unicode code point.
The minimum value of a Unicode high-surrogate code unit in the UTF-16 encoding. A high-surrogate is also known as a leading-surrogate.
The minimum value of a Unicode low-surrogate code unit in the UTF-16 encoding. A low-surrogate is also known as a trailing-surrogate.
The minimum radix available for conversion to and from strings.
The constant value of this field is the smallest value permitted
for the radix argument in radix-conversion methods such as the
digit
method, the forDigit
method, and the toString
method of class
Integer
.
The minimum value of a supplementary code point.
The minimum value of a Unicode surrogate code unit in the UTF-16 encoding.
The constant value of this field is the smallest value of type
char
, '\u0000'
.
General category "Lm" in the Unicode specification.
General category "Sk" in the Unicode specification.
General category "Mn" in the Unicode specification.
General category "Lo" in the Unicode specification.
General category "No" in the Unicode specification.
General category "Po" in the Unicode specification.
General category "So" in the Unicode specification.
General category "Zp" in the Unicode specification.
General category "Co" in the Unicode specification.
The number of bits used to represent a char value in unsigned binary form.
General category "Zs" in the Unicode specification.
General category "Ps" in the Unicode specification.
General category "Cs" in the Unicode specification.
General category "Lt" in the Unicode specification.
General category "Cn" in the Unicode specification.
General category "Lu" in the Unicode specification.
Constructs a newly allocated Character
object that
represents the specified char
value.
value | the value to be represented by the
Character object.
|
---|
Determines the number of 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. |
---|
Returns the value of this Character
object.
char
value represented by
this object.
Returns the code point at the given index of the
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 array |
---|---|
index | the index to the char values (Unicode
code units) in the char array to be converted |
NullPointerException | if a is null. |
---|---|
IndexOutOfBoundsException | if the value
index is negative or not less than
the length of the char array. |
Returns the code point at the given index of the
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 array |
---|---|
index | the index to the char values (Unicode
code units) in the char array to be converted |
limit | the index after the last array element that can be used in the
char array |
NullPointerException | 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. |
Returns the code point at the given index of the
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 converted |
NullPointerException | if seq is null. |
---|---|
IndexOutOfBoundsException | if the value
index is negative or not less than
seq.length() . |
Returns the code point preceding the given index of the
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 instance |
---|---|
index | the index following the code point that should be returned |
NullPointerException | if seq is null. |
---|---|
IndexOutOfBoundsException | if the index
argument is less than 1 or greater than seq.length() . |
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. 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 array |
---|---|
index | the index following the code point that should be returned |
start | the index of the first array element in the
char array |
NullPointerException | 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. |
Returns the code point preceding the given index of the
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 array |
---|---|
index | the index following the code point that should be returned |
NullPointerException | if a is null. |
---|---|
IndexOutOfBoundsException | if the index
argument is less than 1 or greater than the length of the
char array |
Returns the number of Unicode code points in the text range of
the specified char sequence. The text range begins at the
specified 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 sequence |
---|---|
beginIndex | 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 . |
Returns the number of Unicode code points in a subarray of the
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 array |
---|---|
offset | the index of the first char in the
given char array |
count | the length of the subarray in char s |
NullPointerException | if a is null. |
---|---|
IndexOutOfBoundsException | if offset or
count is negative, or if offset +
count is larger than the length of the given array. |
Compares two Character
objects numerically.
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.Returns the numeric value of the character 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.
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. |
Returns the numeric value of the specified character (Unicode code point) in the specified 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, 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.
codePoint | the character (Unicode code point) to be converted. |
---|---|
radix | the radix. |
Compares this object against the specified object.
The result is true
if and only if the argument is not
null
and is a Character
object that
represents the same char
value as this object.
obj | the object to compare with. |
---|
true
if the objects are the same;
false
otherwise.
Determines the character representation for a specific digit in
the specified radix. If the value of 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.Returns the Unicode directionality property for the given
character (Unicode code point). Character directionality is
used to calculate the visual ordering of text. The
directionality value of undefined character is DIRECTIONALITY_UNDEFINED
.
codePoint | the character (Unicode code point) for which the directionality property is requested. |
---|
DIRECTIONALITY_UNDEFINED
DIRECTIONALITY_LEFT_TO_RIGHT
DIRECTIONALITY_RIGHT_TO_LEFT
DIRECTIONALITY_RIGHT_TO_LEFT_ARABIC
DIRECTIONALITY_EUROPEAN_NUMBER
DIRECTIONALITY_EUROPEAN_NUMBER_SEPARATOR
DIRECTIONALITY_EUROPEAN_NUMBER_TERMINATOR
DIRECTIONALITY_ARABIC_NUMBER
DIRECTIONALITY_COMMON_NUMBER_SEPARATOR
DIRECTIONALITY_NONSPACING_MARK
DIRECTIONALITY_BOUNDARY_NEUTRAL
DIRECTIONALITY_PARAGRAPH_SEPARATOR
DIRECTIONALITY_SEGMENT_SEPARATOR
DIRECTIONALITY_WHITESPACE
DIRECTIONALITY_OTHER_NEUTRALS
DIRECTIONALITY_LEFT_TO_RIGHT_EMBEDDING
DIRECTIONALITY_LEFT_TO_RIGHT_OVERRIDE
DIRECTIONALITY_RIGHT_TO_LEFT_EMBEDDING
DIRECTIONALITY_RIGHT_TO_LEFT_OVERRIDE
DIRECTIONALITY_POP_DIRECTIONAL_FORMAT
Returns the Unicode directionality property for the given
character. Character directionality is used to calculate the
visual ordering of text. The directionality value of undefined
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.DIRECTIONALITY_UNDEFINED
DIRECTIONALITY_LEFT_TO_RIGHT
DIRECTIONALITY_RIGHT_TO_LEFT
DIRECTIONALITY_RIGHT_TO_LEFT_ARABIC
DIRECTIONALITY_EUROPEAN_NUMBER
DIRECTIONALITY_EUROPEAN_NUMBER_SEPARATOR
DIRECTIONALITY_EUROPEAN_NUMBER_TERMINATOR
DIRECTIONALITY_ARABIC_NUMBER
DIRECTIONALITY_COMMON_NUMBER_SEPARATOR
DIRECTIONALITY_NONSPACING_MARK
DIRECTIONALITY_BOUNDARY_NEUTRAL
DIRECTIONALITY_PARAGRAPH_SEPARATOR
DIRECTIONALITY_SEGMENT_SEPARATOR
DIRECTIONALITY_WHITESPACE
DIRECTIONALITY_OTHER_NEUTRALS
DIRECTIONALITY_LEFT_TO_RIGHT_EMBEDDING
DIRECTIONALITY_LEFT_TO_RIGHT_OVERRIDE
DIRECTIONALITY_RIGHT_TO_LEFT_EMBEDDING
DIRECTIONALITY_RIGHT_TO_LEFT_OVERRIDE
DIRECTIONALITY_POP_DIRECTIONAL_FORMAT
Returns the 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 that is not a
nonnegative integer; -1 if the character has no numeric value.Returns the 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 that is not a
nonnegative integer; -1 if the character has no numeric value.Returns a value indicating a character's general category.
Note: This method cannot handle supplementary characters. To support
all Unicode characters, including supplementary characters, use
the getType(int)
method.
ch | the character to be tested. |
---|
int
representing the
character's general category.COMBINING_SPACING_MARK
CONNECTOR_PUNCTUATION
CONTROL
CURRENCY_SYMBOL
DASH_PUNCTUATION
DECIMAL_DIGIT_NUMBER
ENCLOSING_MARK
END_PUNCTUATION
FINAL_QUOTE_PUNCTUATION
FORMAT
INITIAL_QUOTE_PUNCTUATION
LETTER_NUMBER
LINE_SEPARATOR
LOWERCASE_LETTER
MATH_SYMBOL
MODIFIER_LETTER
MODIFIER_SYMBOL
NON_SPACING_MARK
OTHER_LETTER
OTHER_NUMBER
OTHER_PUNCTUATION
OTHER_SYMBOL
PARAGRAPH_SEPARATOR
PRIVATE_USE
SPACE_SEPARATOR
START_PUNCTUATION
SURROGATE
TITLECASE_LETTER
UNASSIGNED
UPPERCASE_LETTER
Returns a value indicating a character's general category.
codePoint | the character (Unicode code point) to be tested. |
---|
int
representing the
character's general category.COMBINING_SPACING_MARK
CONNECTOR_PUNCTUATION
CONTROL
CURRENCY_SYMBOL
DASH_PUNCTUATION
DECIMAL_DIGIT_NUMBER
ENCLOSING_MARK
END_PUNCTUATION
FINAL_QUOTE_PUNCTUATION
FORMAT
INITIAL_QUOTE_PUNCTUATION
LETTER_NUMBER
LINE_SEPARATOR
LOWERCASE_LETTER
MATH_SYMBOL
MODIFIER_LETTER
MODIFIER_SYMBOL
NON_SPACING_MARK
OTHER_LETTER
OTHER_NUMBER
OTHER_PUNCTUATION
OTHER_SYMBOL
PARAGRAPH_SEPARATOR
PRIVATE_USE
SPACE_SEPARATOR
START_PUNCTUATION
SURROGATE
TITLECASE_LETTER
UNASSIGNED
UPPERCASE_LETTER
Returns a hash code for this Character
.
Determines if a character (Unicode code point) is defined in Unicode.
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.Determines if a character is defined in Unicode.
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 tested |
---|
true
if the character has a defined meaning
in Unicode; false
otherwise.Determines if the specified character is a digit.
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.Determines if the specified character (Unicode code point) is a digit.
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.Determines if the given char
value is a
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.
This method returns true
if and only if
isch >= '\uD800' && ch <= '\uDBFF'
true
.ch | the char value to be tested. |
---|
true
if the char
value
is between '\uD800' and '\uDBFF' inclusive;
false
otherwise.Determines if the specified character is an ISO control
character. A character is considered to be an ISO control
character if its code is in the range '\u0000'
through '\u001F'
or in the range
'\u007F'
through '\u009F'
.
Note: This method cannot handle supplementary characters. To support
all Unicode characters, including supplementary characters, use
the isISOControl(int)
method.
ch | the character to be tested. |
---|
true
if the character is an ISO control character;
false
otherwise.Determines if the referenced character (Unicode code point) is an ISO control
character. A character is considered to be an ISO control
character if its code is in the range '\u0000'
through '\u001F'
or in the range
'\u007F'
through '\u009F'
.
codePoint | the character (Unicode code point) to be tested. |
---|
true
if the character is an ISO control character;
false
otherwise.Determines if the specified character should be regarded as an ignorable character in a Java identifier or a Unicode identifier.
The following Unicode characters are ignorable in a Java identifier or a Unicode identifier:
'\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.Determines if the specified character (Unicode code point) should be regarded as an ignorable character in a Java identifier or a Unicode identifier.
The following Unicode characters are ignorable in a Java identifier or a Unicode identifier:
'\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.Determines if the character (Unicode code point) may be part of a Java identifier as other than the first character.
A character may be part of a Java identifier if any of the following are true:
'$'
)
'_'
)
isIdentifierIgnorable(codePoint)
returns true
for
the character
codePoint | the character (Unicode code point) to be tested. |
---|
true
if the character may be part of a
Java identifier; false
otherwise.isIdentifierIgnorable(int)
isJavaIdentifierStart(int)
isLetterOrDigit(int)
isUnicodeIdentifierPart(int)
Determines if the specified character may be part of a Java identifier as other than the first character.
A character may be part of a Java identifier if any of the following are true:
'$'
)
'_'
)
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.isIdentifierIgnorable(char)
isJavaIdentifierStart(char)
isLetterOrDigit(char)
isUnicodeIdentifierPart(char)
Determines if the specified character is permissible as the first character in a Java identifier.
A character may start a Java identifier if and only if one of the following conditions is true:
isLetter(ch)
returns true
getType(ch)
returns LETTER_NUMBER
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.isJavaIdentifierPart(char)
isLetter(char)
isUnicodeIdentifierStart(char)
Determines if the character (Unicode code point) is permissible as the first character in a Java identifier.
A character may start a Java identifier if and only if one of the following conditions is true:
isLetter(codePoint)
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.isJavaIdentifierPart(int)
isLetter(int)
isUnicodeIdentifierStart(int)
This method is deprecated.
Replaced by isJavaIdentifierStart(char).
Determines if the specified character is permissible as the first character in a Java identifier.
A character may start a Java identifier if and only if one of the following is true:
isLetter(ch)
returns true
getType(ch)
returns LETTER_NUMBER
ch | the character to be tested. |
---|
true
if the character may start a Java
identifier; false
otherwise.
This method is deprecated.
Replaced by isJavaIdentifierPart(char).
Determines if the specified character may be part of a Java identifier as other than the first character.
A character may be part of a Java identifier if and only if any of the following are 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.Determines if the specified character is a letter.
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.Determines if the specified character (Unicode code point) is a letter.
A character is considered to be a letter if its general
category type, provided 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.Determines if the specified character is a letter or digit.
A character is considered to be a letter or digit if either
Character.isLetter(char ch)
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.Determines if the specified character (Unicode code point) is a letter or digit.
A character is considered to be a letter or digit if either
isLetter(codePoint)
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.Determines if the given char
value is a
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.
This method returns true
if and only if
isch >= '\uDC00' && ch <= '\uDFFF'
true
.ch | the char value to be tested. |
---|
true
if the char
value
is between '\uDC00' and '\uDFFF' inclusive;
false
otherwise.Determines if the specified character (Unicode code point) is a lowercase character.
A character is lowercase if its general category type, provided
by getType(codePoint)
, is
LOWERCASE_LETTER
.
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.Determines if the specified character is a lowercase character.
A character is lowercase if its general category type, provided
by Character.getType(ch)
, is
LOWERCASE_LETTER
.
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.Determines whether the character is mirrored according to the
Unicode specification. Mirrored characters should have their
glyphs horizontally mirrored when displayed in text that is
right-to-left. For example, '\u0028'
LEFT
PARENTHESIS is semantically defined to be 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 requested |
---|
true
if the char is mirrored, false
if the char
is not mirrored or is not defined.Determines whether the specified character (Unicode code point)
is mirrored according to the Unicode specification. Mirrored
characters should have their glyphs horizontally mirrored when
displayed in text that is right-to-left. For example,
'\u0028'
LEFT PARENTHESIS is semantically
defined to be 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.
This method is deprecated.
Replaced by isWhitespace(char).
Determines if the specified character is ISO-LATIN-1 white space.
This method returns true
for the following five
characters only:
'\t' | '\u0009' |
HORIZONTAL TABULATION |
'\n' | '\u000A' |
NEW LINE |
'\f' | '\u000C' |
FORM FEED |
'\r' | '\u000D' |
CARRIAGE RETURN |
' ' | '\u0020' |
SPACE |
ch | the character to be tested. |
---|
true
if the character is ISO-LATIN-1 white
space; false
otherwise.Determines if the specified character is a Unicode space character. A character is considered to be a space character if and only if it is specified to be a space character by the Unicode standard. This method returns true if the character's general category type is any of the following:
SPACE_SEPARATOR
LINE_SEPARATOR
PARAGRAPH_SEPARATOR
Note: This method cannot handle supplementary characters. To support
all Unicode characters, including supplementary characters, use
the isSpaceChar(int)
method.
ch | the character to be tested. |
---|
true
if the character is a space character;
false
otherwise.Determines if the specified character (Unicode code point) is a Unicode space character. A character is considered to be a space character if and only if it is specified to be a space character by the Unicode standard. This method returns true if the character's general category type is any of the following:
codePoint | the character (Unicode code point) to be tested. |
---|
true
if the character is a space character;
false
otherwise.Determines whether the specified character (Unicode code point) is in the supplementary character range. The method call is equivalent to the expression:
codePoint >= 0x10000 && codePoint <= 0x10FFFF
codePoint | the character (Unicode code point) to be tested |
---|
true
if the specified character is in the Unicode
supplementary character range; false
otherwise.Determines whether the specified pair of char
values is a valid surrogate pair. This method is equivalent to
the expression:
isHighSurrogate(high) && isLowSurrogate(low)
high | the high-surrogate code value to be tested |
---|---|
low | the low-surrogate code value to be tested |
true
if the specified high and
low-surrogate code values represent a valid surrogate pair;
false
otherwise.Determines if the specified character (Unicode code point) is a titlecase character.
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.Determines if the specified character is a titlecase character.
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.Determines if the specified character (Unicode code point) may be part of a Unicode identifier as other than the first character.
A character may be part of a Unicode identifier if and only if one of the following statements is true:
'_'
)
isIdentifierIgnorable
returns
true
for this character.
codePoint | the character (Unicode code point) to be tested. |
---|
true
if the character may be part of a
Unicode identifier; false
otherwise.Determines if the specified character may be part of a Unicode identifier as other than the first character.
A character may be part of a Unicode identifier if and only if one of the following statements is true:
'_'
)
isIdentifierIgnorable
returns
true
for this character.
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.Determines if the specified character is permissible as the first character in a Unicode identifier.
A character may start a Unicode identifier if and only if one of the following conditions is true:
isLetter(ch)
returns true
getType(ch)
returns
LETTER_NUMBER
.
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.Determines if the specified character (Unicode code point) is permissible as the first character in a Unicode identifier.
A character may start a Unicode identifier if and only if one of the following conditions is true:
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 Unicode
identifier; false
otherwise.Determines if the specified character (Unicode code point) is an uppercase character.
A character is uppercase if its general category type, provided by
getType(codePoint)
, is UPPERCASE_LETTER
.
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.Determines if the specified character is an uppercase character.
A character is uppercase if its general category type, provided by
Character.getType(ch)
, is UPPERCASE_LETTER
.
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.Determines whether the specified code point is a valid Unicode
code point value in the range of 0x0000
to
0x10FFFF
inclusive. This method is equivalent to
the expression:
codePoint >= 0x0000 && codePoint <= 0x10FFFF
codePoint | the Unicode code point to be tested |
---|
true
if the specified code point value
is a valid code point value;
false
otherwise.Determines if the specified character is white space according to Java. A character is a Java whitespace character if and only if it satisfies one of the following criteria:
SPACE_SEPARATOR
,
LINE_SEPARATOR
, or PARAGRAPH_SEPARATOR
)
but is not also a non-breaking space ('\u00A0'
,
'\u2007'
, '\u202F'
).
'\u0009'
, HORIZONTAL TABULATION.
'\u000A'
, LINE FEED.
'\u000B'
, VERTICAL TABULATION.
'\u000C'
, FORM FEED.
'\u000D'
, CARRIAGE RETURN.
'\u001C'
, FILE SEPARATOR.
'\u001D'
, GROUP SEPARATOR.
'\u001E'
, RECORD SEPARATOR.
'\u001F'
, 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.Determines if the specified character (Unicode code point) is white space according to Java. A character is a Java whitespace character if and only if it satisfies one of the following criteria:
SPACE_SEPARATOR
,
LINE_SEPARATOR
, or PARAGRAPH_SEPARATOR
)
but is not also a non-breaking space ('\u00A0'
,
'\u2007'
, '\u202F'
).
'\u0009'
, HORIZONTAL TABULATION.
'\u000A'
, LINE FEED.
'\u000B'
, VERTICAL TABULATION.
'\u000C'
, FORM FEED.
'\u000D'
, CARRIAGE RETURN.
'\u001C'
, FILE SEPARATOR.
'\u001D'
, GROUP SEPARATOR.
'\u001E'
, RECORD SEPARATOR.
'\u001F'
, UNIT SEPARATOR.
codePoint | the character (Unicode code point) to be tested. |
---|
true
if the character is a Java whitespace
character; false
otherwise.Returns the index within the given char sequence that is offset
from the given 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 sequence |
---|---|
index | the index to be offset |
codePointOffset | the offset in code points |
NullPointerException | if seq is null. |
---|---|
IndexOutOfBoundsException | if index
is negative or larger then 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. |
Returns the index within the given 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 array |
---|---|
start | the index of the first char of the
subarray |
count | the length of the subarray in char s |
index | the index to be offset |
codePointOffset | the offset in code points |
NullPointerException | 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. |
Returns the value obtained by reversing the order of the bytes in the specified char value.
Converts the specified character (Unicode code point) to its
UTF-16 representation stored in a 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 point |
---|
char
array having
codePoint
's UTF-16 representation.IllegalArgumentException | if the specified
codePoint is not a valid Unicode code point. |
---|
Converts the specified character (Unicode code point) to its
UTF-16 representation. If the specified code point is a BMP
(Basic Multilingual Plane or Plane 0) value, the same value is
stored in 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] .) |
Converts the specified surrogate pair to its supplementary code
point value. This method does not validate the specified
surrogate pair. The caller must validate it using isSurrogatePair
if necessary.
high | the high-surrogate code unit |
---|---|
low | the low-surrogate code unit |
Converts the character argument to lowercase using case mapping information from the UnicodeData file.
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, 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. |
---|
Converts the character (Unicode code point) argument to lowercase using case mapping information from the UnicodeData file.
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, 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. |
---|
Returns a String
object representing the
specified char
. The result is a string of length
1 consisting solely of the specified char
.
c | the char to be converted |
---|
char
Returns a 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.
Converts the character argument to titlecase using case mapping
information from the UnicodeData file. If a character has no
explicit titlecase mapping and is not itself a titlecase char
according to UnicodeData, then the uppercase mapping is
returned as an equivalent titlecase mapping. If the
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. |
---|
Converts the character (Unicode code point) argument to titlecase using case mapping information from the UnicodeData file. If a character has no explicit titlecase mapping and is not itself a titlecase char according to UnicodeData, then the uppercase mapping is returned as an equivalent titlecase mapping. If the character argument is already a titlecase character, the same character value will be returned.
Note 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. |
---|
Converts the character argument to uppercase using case mapping information from the UnicodeData file.
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, 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. |
---|
Converts the character (Unicode code point) argument to uppercase using case mapping information from the UnicodeData file.
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, 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. |
---|
Returns a 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.
c | a char value. |
---|