java.lang
Class Character

java.lang.Object
  java.lang.Character

All Implemented Interfaces:

Comparable , Serializable

public final class Character

extends Object

implements Serializable , Comparable < 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. 3.0.

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:

• http://www.unicode.org

Unicode Character Representations

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:

• The methods that only accept a 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.
• The methods that accept an 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 J2SE 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 .

Since:

1.0

See Also:

Serialized Form

Nested Class Summary
static class	Character.Subset           Instances of this class represent particular subsets of the Unicode character set.
static class	Character.UnicodeBlock           A family of character subsets representing the character blocks in the Unicode specification.

 

Field Summary
static byte	COMBINING_SPACING_MARK           General category "Mc" in the Unicode specification.
static byte	CONNECTOR_PUNCTUATION           General category "Pc" in the Unicode specification.
static byte	CONTROL           General category "Cc" in the Unicode specification.
static byte	CURRENCY_SYMBOL           General category "Sc" in the Unicode specification.
static byte	DASH_PUNCTUATION           General category "Pd" in the Unicode specification.
static byte	DECIMAL_DIGIT_NUMBER           General category "Nd" in the Unicode specification.
static byte	DIRECTIONALITY_ARABIC_NUMBER           Weak bidirectional character type "AN" in the Unicode specification.
static byte	DIRECTIONALITY_BOUNDARY_NEUTRAL           Weak bidirectional character type "BN" in the Unicode specification.
static byte	DIRECTIONALITY_COMMON_NUMBER_SEPARATOR           Weak bidirectional character type "CS" in the Unicode specification.
static byte	DIRECTIONALITY_EUROPEAN_NUMBER           Weak bidirectional character type "EN" in the Unicode specification.
static byte	DIRECTIONALITY_EUROPEAN_NUMBER_SEPARATOR           Weak bidirectional character type "ES" in the Unicode specification.
static byte	DIRECTIONALITY_EUROPEAN_NUMBER_TERMINATOR           Weak bidirectional character type "ET" in the Unicode specification.
static byte	DIRECTIONALITY_LEFT_TO_RIGHT           Strong bidirectional character type "L" in the Unicode specification.
static byte	DIRECTIONALITY_LEFT_TO_RIGHT_EMBEDDING           Strong bidirectional character type "LRE" in the Unicode specification.
static byte	DIRECTIONALITY_LEFT_TO_RIGHT_OVERRIDE           Strong bidirectional character type "LRO" in the Unicode specification.
static byte	DIRECTIONALITY_NONSPACING_MARK           Weak bidirectional character type "NSM" in the Unicode specification.
static byte	DIRECTIONALITY_OTHER_NEUTRALS           Neutral bidirectional character type "ON" in the Unicode specification.
static byte	DIRECTIONALITY_PARAGRAPH_SEPARATOR           Neutral bidirectional character type "B" in the Unicode specification.
static byte	DIRECTIONALITY_POP_DIRECTIONAL_FORMAT           Weak bidirectional character type "PDF" in the Unicode specification.
static byte	DIRECTIONALITY_RIGHT_TO_LEFT           Strong bidirectional character type "R" in the Unicode specification.
static byte	DIRECTIONALITY_RIGHT_TO_LEFT_ARABIC           Strong bidirectional character type "AL" in the Unicode specification.
static byte	DIRECTIONALITY_RIGHT_TO_LEFT_EMBEDDING           Strong bidirectional character type "RLE" in the Unicode specification.
static byte	DIRECTIONALITY_RIGHT_TO_LEFT_OVERRIDE           Strong bidirectional character type "RLO" in the Unicode specification.
static byte	DIRECTIONALITY_SEGMENT_SEPARATOR           Neutral bidirectional character type "S" in the Unicode specification.
static byte	DIRECTIONALITY_UNDEFINED           Undefined bidirectional character type.
static byte	DIRECTIONALITY_WHITESPACE           Neutral bidirectional character type "WS" in the Unicode specification.
static byte	ENCLOSING_MARK           General category "Me" in the Unicode specification.
static byte	END_PUNCTUATION           General category "Pe" in the Unicode specification.
static byte	FINAL_QUOTE_PUNCTUATION           General category "Pf" in the Unicode specification.
static byte	FORMAT           General category "Cf" in the Unicode specification.
static byte	INITIAL_QUOTE_PUNCTUATION           General category "Pi" in the Unicode specification.
static byte	LETTER_NUMBER           General category "Nl" in the Unicode specification.
static byte	LINE_SEPARATOR           General category "Zl" in the Unicode specification.
static byte	LOWERCASE_LETTER           General category "Ll" in the Unicode specification.
static byte	MATH_SYMBOL           General category "Sm" in the Unicode specification.
static int	MAX_CODE_POINT           The maximum value of a Unicode code point.
static char	MAX_HIGH_SURROGATE           The maximum value of a Unicode high-surrogate code unit in the UTF-16 encoding.
static char	MAX_LOW_SURROGATE           The maximum value of a Unicode low-surrogate code unit in the UTF-16 encoding.
static int	MAX_RADIX           The maximum radix available for conversion to and from strings.
static char	MAX_SURROGATE           The maximum value of a Unicode surrogate code unit in the UTF-16 encoding.
static char	MAX_VALUE           The constant value of this field is the largest value of type char, '\uFFFF'.
static char	MIN_HIGH_SURROGATE           The minimum value of a Unicode high-surrogate code unit in the UTF-16 encoding.
static char	MIN_LOW_SURROGATE           The minimum value of a Unicode low-surrogate code unit in the UTF-16 encoding.
static int	MIN_RADIX           The minimum radix available for conversion to and from strings.
static int	MIN_SUPPLEMENTARY_CODE_POINT           The minimum value of a supplementary code point.
static char	MIN_SURROGATE           The minimum value of a Unicode surrogate code unit in the UTF-16 encoding.
static char	MIN_VALUE           The constant value of this field is the smallest value of type char, '\u0000'.
static byte	MODIFIER_LETTER           General category "Lm" in the Unicode specification.
static byte	MODIFIER_SYMBOL           General category "Sk" in the Unicode specification.
static byte	NON_SPACING_MARK           General category "Mn" in the Unicode specification.
static byte	OTHER_LETTER           General category "Lo" in the Unicode specification.
static byte	OTHER_NUMBER           General category "No" in the Unicode specification.
static byte	OTHER_PUNCTUATION           General category "Po" in the Unicode specification.
static byte	OTHER_SYMBOL           General category "So" in the Unicode specification.
static byte	PARAGRAPH_SEPARATOR           General category "Zp" in the Unicode specification.
static byte	PRIVATE_USE           General category "Co" in the Unicode specification.
static int	SIZE           The number of bits used to represent a char value in unsigned binary form.
static byte	SPACE_SEPARATOR           General category "Zs" in the Unicode specification.
static byte	START_PUNCTUATION           General category "Ps" in the Unicode specification.
static byte	SURROGATE           General category "Cs" in the Unicode specification.
static byte	TITLECASE_LETTER           General category "Lt" in the Unicode specification.
static  Class < Character	TYPE           The Class instance representing the primitive type char.
static byte	UNASSIGNED           General category "Cn" in the Unicode specification.
static byte	UPPERCASE_LETTER           General category "Lu" in the Unicode specification.

 

Constructor Summary
Character (char value)           Constructs a newly allocated Character object that represents the specified char value.

 

Method Summary
static int	charCount (int codePoint)           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 (char[] a, int index)           Returns the code point at the given index of the char array.
int	compareTo ( Character           Compares two Character objects numerically.
static int	codePointAt ( CharSequence           Returns the code point at the given index of the CharSequence.
int	compareTo ( Object           Compares this Character object to another object.
static int	codePointBefore (char[] a, int index)           Returns the code point preceding the given index of the char array.
static int	codePointBefore ( CharSequence           Returns the code point preceding the given index of the CharSequence.
int	compareTo ( Character           Compares two Character objects numerically.
static int	digit (char ch, int radix)           Returns the numeric value of the character ch in the specified radix.
static int	digit (int codePoint, int radix)           Returns the numeric value of the specified character (Unicode code point) in the specified radix.
boolean	equals ( Object  obj)           Compares this object against the specified object.
static char	forDigit (int digit, int radix)           Determines the character representation for a specific digit in the specified radix.
static byte	getDirectionality (char ch)           Returns the Unicode directionality property for the given character.
static byte	getDirectionality (int codePoint)           Returns the Unicode directionality property for the given character (Unicode code point).
static int	getNumericValue (char ch)           Returns the int value that the specified Unicode character represents.
static int	getNumericValue (int codePoint)           Returns the int value that the specified character (Unicode code point) represents.
static int	getType (char ch)           Returns a value indicating a character's general category.
static int	getType (int codePoint)           Returns a value indicating a character's general category.
int	hashCode ()           Returns a hash code for this Character.
static boolean	isDefined (char ch)           Determines if a character is defined in Unicode.
static boolean	isDefined (int codePoint)           Determines if a character (Unicode code point) is defined in Unicode.
static boolean	isDigit (char ch)           Determines if the specified character is a digit.
static boolean	isDigit (int codePoint)           Determines if the specified character (Unicode code point) is a digit.
static boolean	isHighSurrogate (char ch)           Determines if the given char value is a high-surrogate code unit (also known as leading-surrogate code unit ).
static boolean	isIdentifierIgnorable (char ch)           Determines if the specified character should be regarded as an ignorable character in a Java identifier or a Unicode identifier.
static boolean	isIdentifierIgnorable (int codePoint)           Determines if the specified character (Unicode code point) should be regarded as an ignorable character in a Java identifier or a Unicode identifier.
static boolean	isISOControl (char ch)           Determines if the specified character is an ISO control character.
static boolean	isISOControl (int codePoint)           Determines if the referenced character (Unicode code point) is an ISO control character.
static boolean	isJavaIdentifierPart (char ch)           Determines if the specified character may be part of a Java identifier as other than the first character.
static boolean	isJavaIdentifierPart (int codePoint)           Determines if the character (Unicode code point) may be part of a Java identifier as other than the first character.
static boolean	isJavaIdentifierStart (char ch)           Determines if the specified character is permissible as the first character in a Java identifier.
static boolean	isJavaIdentifierStart (int codePoint)           Determines if the character (Unicode code point) is permissible as the first character in a Java identifier.
static boolean	isJavaLetter (char ch)            Deprecated.   Replaced by isJavaIdentifierStart(char).
static boolean	isJavaLetterOrDigit (char ch)            Deprecated.   Replaced by isJavaIdentifierPart(char).
static boolean	isLetter (char ch)           Determines if the specified character is a letter.
static boolean	isLetter (int codePoint)           Determines if the specified character (Unicode code point) is a letter.
static boolean	isLetterOrDigit (char ch)           Determines if the specified character is a letter or digit.
static boolean	isLetterOrDigit (int codePoint)           Determines if the specified character (Unicode code point) is a letter or digit.
static boolean	isLowerCase (char ch)           Determines if the specified character is a lowercase character.
static boolean	isLowerCase (int codePoint)           Determines if the specified character (Unicode code point) is a lowercase character.
static boolean	isLowSurrogate (char ch)           Determines if the given char value is a low-surrogate code unit (also known as trailing-surrogate code unit ).
static boolean	isMirrored (char ch)           Determines whether the character is mirrored according to the Unicode specification.
static boolean	isMirrored (int codePoint)           Determines whether the specified character (Unicode code point) is mirrored according to the Unicode specification.
static boolean	isSpace (char ch)            Deprecated.   Replaced by isWhitespace(char).
static boolean	isSpaceChar (char ch)           Determines if the specified character is a Unicode space character.
static boolean	isSpaceChar (int codePoint)           Determines if the specified character (Unicode code point) is a Unicode space character.
static boolean	isSupplementaryCodePoint (int codePoint)           Determines whether the specified character (Unicode code point) is in the supplementary character range.
static boolean	isSurrogatePair (char high, char low)           Determines whether the specified pair of char values is a valid surrogate pair.
static boolean	isTitleCase (char ch)           Determines if the specified character is a titlecase character.
static boolean	isTitleCase (int codePoint)           Determines if the specified character (Unicode code point) is a titlecase character.
static boolean	isUnicodeIdentifierPart (char ch)           Determines if the specified character may be part of a Unicode identifier as other than the first character.
static boolean	isUnicodeIdentifierPart (int codePoint)           Determines if the specified character (Unicode code point) may be part of a Unicode identifier as other than the first character.
static boolean	isUnicodeIdentifierStart (char ch)           Determines if the specified character is permissible as the first character in a Unicode identifier.
static boolean	isUnicodeIdentifierStart (int codePoint)           Determines if the specified character (Unicode code point) is permissible as the first character in a Unicode identifier.
static boolean	isUpperCase (char ch)           Determines if the specified character is an uppercase character.
static boolean	isUpperCase (int codePoint)           Determines if the specified character (Unicode code point) is an uppercase character.
static boolean	isValidCodePoint (int codePoint)           Determines whether the specified code point is a valid Unicode code point value in the range of 0x0000 to 0x10FFFF inclusive.
static boolean	isWhitespace (char ch)           Determines if the specified character is white space according to Java.
static boolean	isWhitespace (int codePoint)           Determines if the specified character (Unicode code point) is white space according to Java.
static char	reverseBytes (char ch)           Returns the value obtained by reversing the order of the bytes in the specified char value.
static char[]	toChars (int codePoint)           Converts the specified character (Unicode code point) to its UTF-16 representation stored in a char array.
static int	toChars (int codePoint, char[] dst, int dstIndex)           Converts the specified character (Unicode code point) to its UTF-16 representation.
static int	toCodePoint (char high, char low)           Converts the specified surrogate pair to its supplementary code point value.
static char	toLowerCase (char ch)           Converts the character argument to lowercase using case mapping information from the UnicodeData file.
static int	toLowerCase (int codePoint)           Converts the character (Unicode code point) argument to lowercase using case mapping information from the UnicodeData file.
String	toString ()           Returns a String object representing this Character's value.
static  String	toString (char c)           Returns a String object representing the specified char.
static char	toTitleCase (char ch)           Converts the character argument to titlecase using case mapping information from the UnicodeData file.
static int	toTitleCase (int codePoint)           Converts the character (Unicode code point) argument to titlecase using case mapping information from the UnicodeData file.
static char	toUpperCase (char ch)           Converts the character argument to uppercase using case mapping information from the UnicodeData file.
static int	toUpperCase (int codePoint)           Converts the character (Unicode code point) argument to uppercase using case mapping information from the UnicodeData file.
static  Character	valueOf (char c)           Returns a Character instance representing the specified char value.

 

Methods inherited from class java.lang. Object
clone , finalize , getClass , notify , notifyAll , wait , wait , wait

 

Methods inherited from interface java.lang. Comparable
compareTo

 

Field Detail

MIN_RADIX

public static final int MIN_RADIX

The minimum radix available for conversion to and from strings. The constant value of this field is the smallest value permitted for the radix argument in radix-conversion methods such as the digit method, the forDigit method, and the toString method of class Integer.

See Also:

digit(char, int) , forDigit(int, int) , Integer.toString(int, int) , Integer.valueOf(java.lang.String) , Constant Field Values

MAX_RADIX

public static final int MAX_RADIX

The maximum radix available for conversion to and from strings. The constant value of this field is the largest value permitted for the radix argument in radix-conversion methods such as the digit method, the forDigit method, and the toString method of class Integer.

See Also:

digit(char, int) , forDigit(int, int) , Integer.toString(int, int) , Integer.valueOf(java.lang.String) , Constant Field Values

MIN_VALUE

public static final char MIN_VALUE

The constant value of this field is the smallest value of type char, '\u0000'.

Since:

1.0.2

See Also:

Constant Field Values

MAX_VALUE

public static final char MAX_VALUE

The constant value of this field is the largest value of type char, '\uFFFF'.

Since:

1.0.2

See Also:

Constant Field Values

TYPE

public static final Class< Character> TYPE

The Class instance representing the primitive type char.

Since:

1.1

UNASSIGNED

public static final byte UNASSIGNED

General category "Cn" in the Unicode specification.

Since:

1.1

See Also:

Constant Field Values

UPPERCASE_LETTER

public static final byte UPPERCASE_LETTER

General category "Lu" in the Unicode specification.

Since:

1.1

See Also:

Constant Field Values

LOWERCASE_LETTER

public static final byte LOWERCASE_LETTER

General category "Ll" in the Unicode specification.

Since:

1.1

See Also:

Constant Field Values

TITLECASE_LETTER

public static final byte TITLECASE_LETTER

General category "Lt" in the Unicode specification.

Since:

1.1

See Also:

Constant Field Values

MODIFIER_LETTER

public static final byte MODIFIER_LETTER

General category "Lm" in the Unicode specification.

Since:

1.1

See Also:

Constant Field Values

OTHER_LETTER

public static final byte OTHER_LETTER

General category "Lo" in the Unicode specification.

Since:

1.1

See Also:

Constant Field Values

NON_SPACING_MARK

public static final byte NON_SPACING_MARK

General category "Mn" in the Unicode specification.

Since:

1.1

See Also:

Constant Field Values

ENCLOSING_MARK

public static final byte ENCLOSING_MARK

General category "Me" in the Unicode specification.

Since:

1.1

See Also:

Constant Field Values

COMBINING_SPACING_MARK

public static final byte COMBINING_SPACING_MARK

General category "Mc" in the Unicode specification.

Since:

1.1

See Also:

Constant Field Values

DECIMAL_DIGIT_NUMBER

public static final byte DECIMAL_DIGIT_NUMBER

General category "Nd" in the Unicode specification.

Since:

1.1

See Also:

Constant Field Values

LETTER_NUMBER

public static final byte LETTER_NUMBER

General category "Nl" in the Unicode specification.

Since:

1.1

See Also:

Constant Field Values

OTHER_NUMBER

public static final byte OTHER_NUMBER

General category "No" in the Unicode specification.

Since:

1.1

See Also:

Constant Field Values

SPACE_SEPARATOR

public static final byte SPACE_SEPARATOR

General category "Zs" in the Unicode specification.

Since:

1.1

See Also:

Constant Field Values

LINE_SEPARATOR

public static final byte LINE_SEPARATOR

General category "Zl" in the Unicode specification.

Since:

1.1

See Also:

Constant Field Values

PARAGRAPH_SEPARATOR

public static final byte PARAGRAPH_SEPARATOR

General category "Zp" in the Unicode specification.

Since:

1.1

See Also:

Constant Field Values

CONTROL

public static final byte CONTROL

General category "Cc" in the Unicode specification.

Since:

1.1

See Also:

Constant Field Values

FORMAT

public static final byte FORMAT

General category "Cf" in the Unicode specification.

Since:

1.1

See Also:

Constant Field Values

PRIVATE_USE

public static final byte PRIVATE_USE

General category "Co" in the Unicode specification.

Since:

1.1

See Also:

Constant Field Values

SURROGATE

public static final byte SURROGATE

General category "Cs" in the Unicode specification.

Since:

1.1

See Also:

Constant Field Values

DASH_PUNCTUATION

public static final byte DASH_PUNCTUATION

General category "Pd" in the Unicode specification.

Since:

1.1

See Also:

Constant Field Values

START_PUNCTUATION

public static final byte START_PUNCTUATION

General category "Ps" in the Unicode specification.

Since:

1.1

See Also:

Constant Field Values

END_PUNCTUATION

public static final byte END_PUNCTUATION

General category "Pe" in the Unicode specification.

Since:

1.1

See Also:

Constant Field Values

CONNECTOR_PUNCTUATION

public static final byte CONNECTOR_PUNCTUATION

General category "Pc" in the Unicode specification.

Since:

1.1

See Also:

Constant Field Values

OTHER_PUNCTUATION

public static final byte OTHER_PUNCTUATION

General category "Po" in the Unicode specification.

Since:

1.1

See Also:

Constant Field Values

MATH_SYMBOL

public static final byte MATH_SYMBOL

General category "Sm" in the Unicode specification.

Since:

1.1

See Also:

Constant Field Values

CURRENCY_SYMBOL

public static final byte CURRENCY_SYMBOL

General category "Sc" in the Unicode specification.

Since:

1.1

See Also:

Constant Field Values

MODIFIER_SYMBOL

public static final byte MODIFIER_SYMBOL

General category "Sk" in the Unicode specification.

Since:

1.1

See Also:

Constant Field Values

OTHER_SYMBOL

public static final byte OTHER_SYMBOL

General category "So" in the Unicode specification.

Since:

1.1

See Also:

Constant Field Values

INITIAL_QUOTE_PUNCTUATION

public static final byte INITIAL_QUOTE_PUNCTUATION

General category "Pi" in the Unicode specification.

Since:

1.4

See Also:

Constant Field Values

FINAL_QUOTE_PUNCTUATION

public static final byte FINAL_QUOTE_PUNCTUATION

General category "Pf" in the Unicode specification.

Since:

1.4

See Also:

Constant Field Values

DIRECTIONALITY_UNDEFINED

public static final byte DIRECTIONALITY_UNDEFINED

Undefined bidirectional character type. Undefined char values have undefined directionality in the Unicode specification.

Since:

1.4

See Also:

Constant Field Values

DIRECTIONALITY_LEFT_TO_RIGHT

public static final byte DIRECTIONALITY_LEFT_TO_RIGHT

Strong bidirectional character type "L" in the Unicode specification.

Since:

1.4

See Also:

Constant Field Values

DIRECTIONALITY_RIGHT_TO_LEFT

public static final byte DIRECTIONALITY_RIGHT_TO_LEFT

Strong bidirectional character type "R" in the Unicode specification.

Since:

1.4

See Also:

Constant Field Values

DIRECTIONALITY_RIGHT_TO_LEFT_ARABIC

public static final byte DIRECTIONALITY_RIGHT_TO_LEFT_ARABIC

Strong bidirectional character type "AL" in the Unicode specification.

Since:

1.4

See Also:

Constant Field Values

DIRECTIONALITY_EUROPEAN_NUMBER

public static final byte DIRECTIONALITY_EUROPEAN_NUMBER

Weak bidirectional character type "EN" in the Unicode specification.

Since:

1.4

See Also:

Constant Field Values

DIRECTIONALITY_EUROPEAN_NUMBER_SEPARATOR

public static final byte DIRECTIONALITY_EUROPEAN_NUMBER_SEPARATOR

Weak bidirectional character type "ES" in the Unicode specification.

Since:

1.4

See Also:

Constant Field Values

DIRECTIONALITY_EUROPEAN_NUMBER_TERMINATOR

public static final byte DIRECTIONALITY_EUROPEAN_NUMBER_TERMINATOR

Weak bidirectional character type "ET" in the Unicode specification.

Since:

1.4

See Also:

Constant Field Values

DIRECTIONALITY_ARABIC_NUMBER

public static final byte DIRECTIONALITY_ARABIC_NUMBER

Weak bidirectional character type "AN" in the Unicode specification.

Since:

1.4

See Also:

Constant Field Values

DIRECTIONALITY_COMMON_NUMBER_SEPARATOR

public static final byte DIRECTIONALITY_COMMON_NUMBER_SEPARATOR

Weak bidirectional character type "CS" in the Unicode specification.

Since:

1.4

See Also:

Constant Field Values

DIRECTIONALITY_NONSPACING_MARK

public static final byte DIRECTIONALITY_NONSPACING_MARK

Weak bidirectional character type "NSM" in the Unicode specification.

Since:

1.4

See Also:

Constant Field Values

DIRECTIONALITY_BOUNDARY_NEUTRAL

public static final byte DIRECTIONALITY_BOUNDARY_NEUTRAL

Weak bidirectional character type "BN" in the Unicode specification.

Since:

1.4

See Also:

Constant Field Values

DIRECTIONALITY_PARAGRAPH_SEPARATOR

public static final byte DIRECTIONALITY_PARAGRAPH_SEPARATOR

Neutral bidirectional character type "B" in the Unicode specification.

Since:

1.4

See Also:

Constant Field Values

DIRECTIONALITY_SEGMENT_SEPARATOR

public static final byte DIRECTIONALITY_SEGMENT_SEPARATOR

Neutral bidirectional character type "S" in the Unicode specification.

Since:

1.4

See Also:

Constant Field Values

DIRECTIONALITY_WHITESPACE

public static final byte DIRECTIONALITY_WHITESPACE

Neutral bidirectional character type "WS" in the Unicode specification.

Since:

1.4

See Also:

Constant Field Values

DIRECTIONALITY_OTHER_NEUTRALS

public static final byte DIRECTIONALITY_OTHER_NEUTRALS

Neutral bidirectional character type "ON" in the Unicode specification.

Since:

1.4

See Also:

Constant Field Values

DIRECTIONALITY_LEFT_TO_RIGHT_EMBEDDING

public static final byte DIRECTIONALITY_LEFT_TO_RIGHT_EMBEDDING

Strong bidirectional character type "LRE" in the Unicode specification.

Since:

1.4

See Also:

Constant Field Values

DIRECTIONALITY_LEFT_TO_RIGHT_OVERRIDE

public static final byte DIRECTIONALITY_LEFT_TO_RIGHT_OVERRIDE

Strong bidirectional character type "LRO" in the Unicode specification.

Since:

1.4

See Also:

Constant Field Values

DIRECTIONALITY_RIGHT_TO_LEFT_EMBEDDING

public static final byte DIRECTIONALITY_RIGHT_TO_LEFT_EMBEDDING

Strong bidirectional character type "RLE" in the Unicode specification.

Since:

1.4

See Also:

Constant Field Values

DIRECTIONALITY_RIGHT_TO_LEFT_OVERRIDE

public static final byte DIRECTIONALITY_RIGHT_TO_LEFT_OVERRIDE

Strong bidirectional character type "RLO" in the Unicode specification.

Since:

1.4

See Also:

Constant Field Values

DIRECTIONALITY_POP_DIRECTIONAL_FORMAT

public static final byte DIRECTIONALITY_POP_DIRECTIONAL_FORMAT

Weak bidirectional character type "PDF" in the Unicode specification.

Since:

1.4

See Also:

Constant Field Values

MIN_HIGH_SURROGATE

 
public static final char MIN_HIGH_SURROGATE 

The minimum value of a Unicode high-surrogate code unit in the UTF-16 encoding. A high-surrogate is also known as a leading-surrogate .

Since:

1.5

See Also:

Constant Field Values

MAX_HIGH_SURROGATE

 
public static final char MAX_HIGH_SURROGATE 

The maximum value of a Unicode high-surrogate code unit in the UTF-16 encoding. A high-surrogate is also known as a leading-surrogate .

Since:

1.5

See Also:

Constant Field Values

MIN_LOW_SURROGATE

 
public static final char MIN_LOW_SURROGATE 

The minimum value of a Unicode low-surrogate code unit in the UTF-16 encoding. A low-surrogate is also known as a trailing-surrogate .

Since:

1.5

See Also:

Constant Field Values

MAX_LOW_SURROGATE

 
public static final char MAX_LOW_SURROGATE 

The maximum value of a Unicode low-surrogate code unit in the UTF-16 encoding. A low-surrogate is also known as a trailing-surrogate .

Since:

1.5

See Also:

Constant Field Values

MIN_SURROGATE

 
public static final char MIN_SURROGATE 

The minimum value of a Unicode surrogate code unit in the UTF-16 encoding.

Since:

1.5

See Also:

Constant Field Values

MAX_SURROGATE

 
public static final char MAX_SURROGATE 

The maximum value of a Unicode surrogate code unit in the UTF-16 encoding.

Since:

1.5

See Also:

Constant Field Values

MIN_SUPPLEMENTARY_CODE_POINT

 
public static final int MIN_SUPPLEMENTARY_CODE_POINT 

The minimum value of a supplementary code point.

Since:

1.5

See Also:

Constant Field Values

MAX_CODE_POINT

 
public static final int MAX_CODE_POINT 

The maximum value of a Unicode code point.

Since:

1.5

See Also:

Constant Field Values

SIZE

 
public static final int SIZE 

The number of bits used to represent a char value in unsigned binary form.

Since:

1.5

See Also:

Constant Field Values

Character

public Character(char value)

Constructs a newly allocated Character object that represents the specified char value.

Parameters:

value - the value to be represented by the Character object.

valueOf

 
public static CharactervalueOf (char c) 

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 to yield significantly better space and time performance by cacheing frequently requested values.

Parameters:

c - a char value.

Returns:

a Character instance representing c .

Since:

1.5

charValue

public char charValue()

Returns the value of this Character object.

Returns:

the primitive char value represented by this object.

hashCode

public int hashCode()

Returns a hash code for this Character.

Overrides:

hashCode in class Object

Returns:

a hash code value for this object.

See Also:

Object.equals(java.lang.Object) , Hashtable

equals

public boolean equals(Object obj)

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.

Overrides:

equals in class Object

Parameters:

obj - the object to compare with.

Returns:

true if the objects are the same; false otherwise.

See Also:

Object.hashCode() , Hashtable

toString

public String toString()

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.

Overrides:

toString in class Object

Returns:

a string representation of this object.

toString

public static String toString(char c)

Returns a String object representing the specified char. The result is a string of length 1 consisting solely of the specified char.

Parameters:

c - the char to be converted

Returns:

the string representation of the specified char

Since:

1.4

isValidCodePoint

 
public static final boolean isValidCodePoint (int codePoint) 

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
 

Parameters:

codePoint - the Unicode code point to be tested

Returns:

true if the specified code point value is a valid code point value; false otherwise.

Since:

1.5

isSupplementaryCodePoint

 
public static final boolean isSupplementaryCodePoint (int codePoint) 

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
 

Parameters:

codePoint - the character (Unicode code point) to be tested

Returns:

true if the specified character is in the Unicode supplementary character range; false otherwise.

Since:

1.5

isHighSurrogate

 
public static boolean isHighSurrogate (char ch) 

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

ch >= '\uD800' && ch <= '\uDBFF'
 

is true.

Parameters:

ch - the char value to be tested.

Returns:

true if the char value is between '\uD800' and '\uDBFF' inclusive; false otherwise.

Since:

1.5

See Also:

isLowSurrogate(char) , Character.UnicodeBlock.of(int)

isLowSurrogate

 
public static boolean isLowSurrogate (char ch) 

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

ch >= '\uDC00' && ch <= '\uDFFF'
 

is true.

Parameters:

ch - the char value to be tested.

Returns:

true if the char value is between '\uDC00' and '\uDFFF' inclusive; false otherwise.

Since:

1.5

See Also:

isHighSurrogate(char)

isSurrogatePair

 
public static final boolean isSurrogatePair (char high,
 char low) 

Determines whether the specified pair of char values is a valid surrogate pair. This method is equivalent to the expression:

 isHighSurrogate(high) && isLowSurrogate(low)
 

Parameters:

high - the high-surrogate code value to be tested

low - the low-surrogate code value to be tested

Returns:

true if the specified high and low-surrogate code values represent a valid surrogate pair; false otherwise.

Since:

1.5

charCount

 
public static int charCount (int codePoint) 

Determines the number 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.

Parameters:

codePoint - the character (Unicode code point) to be tested.

Returns:

2 if the character is a valid supplementary character; 1 otherwise.

Since:

1.5

See Also:

isSupplementaryCodePoint(int)

toCodePoint

 
public static final int toCodePoint (char high,
 char low) 

Converts the specified surrogate pair to its supplementary code point value. This method does not validate the specified surrogate pair. The caller must validate it using isSurrogatePair if necessary.

Parameters:

high - the high-surrogate code unit

low - the low-surrogate code unit

Returns:

the supplementary code point composed from the specified surrogate pair.

Since:

1.5

codePointAt

 
public static final int codePointAt ( CharSequence seq,
 int index) 

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.

Parameters:

seq - a sequence of char values (Unicode code units)

index - the index to the char values (Unicode code units) in seq to be converted

Returns:

the Unicode code point at the given index

Throws:

NullPointerException - if seq is null.

IndexOutOfBoundsException - if the value index is negative or not less than seq.length() .

Since:

1.5

codePointAt

 
public static final int codePointAt (char[] a,
 int index) 

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.

Parameters:

a - the char array

index - the index to the char values (Unicode code units) in the char array to be converted

Returns:

the Unicode code point at the given index

Throws:

NullPointerException - if a is null.

IndexOutOfBoundsException - if the value index is negative or not less than the length of the char array.

Since:

1.5

codePointBefore

 
public static final int codePointBefore ( CharSequence seq,
 int index) 

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.

Parameters:

seq - the CharSequence instance

index - the index following the code point that should be returned

Returns:

the Unicode code point value before the given index.

Throws:

NullPointerException - if seq is null.

IndexOutOfBoundsException - if the index argument is less than 1 or greater than seq.length() .

Since:

1.5

codePointBefore

 
public static final int codePointBefore (char[] a,
 int index) 

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.

Parameters:

a - the char array

index - the index following the code point that should be returned

Returns:

the Unicode code point value before the given index.

Throws:

NullPointerException - if a is null.

IndexOutOfBoundsException - if the index argument is less than 1 or greater than the length of the char array

Since:

1.5

toChars

 
public static final int toChars (int codePoint,
 char[] dst,
 int dstIndex) 

Converts the specified character (Unicode code point) to its UTF-16 representation. If the specified code point is a BMP (Basic Multilingual Plane or Plane 0) value, the same value is stored 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.

Parameters:

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.

Returns:

1 if the code point is a BMP code point, 2 if the code point is a supplementary code point.

Throws:

IllegalArgumentException - if the 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].)

Since:

1.5

toChars

 
public static final char[] toChars (int codePoint) 

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.

Parameters:

codePoint - a Unicode code point

Returns:

a char array having codePoint's UTF-16 representation.

Throws:

IllegalArgumentException - if the specified codePoint is not a valid Unicode code point.

Since:

1.5

isLowerCase

public static boolean isLowerCase(char ch)

Determines if the specified character is a lowercase character.

A character is lowercase if its general category type, provided 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.

Parameters:

ch - the character to be tested.

Returns:

true if the character is lowercase; false otherwise.

See Also:

isLowerCase(char) , isTitleCase(char) , toLowerCase(char) , getType(char)

isLowerCase

 
public static boolean isLowerCase (int codePoint) 

Determines if the specified character (Unicode code point) is a lowercase character.

A character is lowercase if its general category type, provided 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.

Parameters:

codePoint - the character (Unicode code point) to be tested.

Returns:

true if the character is lowercase; false otherwise.

Since:

1.5

See Also:

isLowerCase(int) , isTitleCase(int) , toLowerCase(int) , getType(int)

isUpperCase

public static boolean isUpperCase(char ch)

Determines if the specified character is an uppercase character.

A character is uppercase if its general category type, provided 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.

Parameters:

ch - the character to be tested.

Returns:

true if the character is uppercase; false otherwise.

Since:

1.0

See Also:

isLowerCase(char) , isTitleCase(char) , toUpperCase(char) , getType(char)

isUpperCase

 
public static boolean isUpperCase (int codePoint) 

Determines if the specified character (Unicode code point) is an uppercase character.

A character is uppercase if its general category type, provided 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.

Parameters:

codePoint - the character (Unicode code point) to be tested.

Returns:

true if the character is uppercase; false otherwise.

Since:

1.5

See Also:

isLowerCase(int) , isTitleCase(int) , toUpperCase(int) , getType(int)

isTitleCase

public static boolean isTitleCase(char ch)

Determines if the specified character is a titlecase character.

A character is a titlecase character if its general category type, provided 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.

Parameters:

ch - the character to be tested.

Returns:

true if the character is titlecase; false otherwise.

Since:

1.0.2

See Also:

isLowerCase(char) , isUpperCase(char) , toTitleCase(char) , getType(char)

isTitleCase

 
public static boolean isTitleCase (int codePoint) 

Determines if the specified character (Unicode code point) is a titlecase character.

A character is a titlecase character if its general category type, provided 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.

Parameters:

codePoint - the character (Unicode code point) to be tested.

Returns:

true if the character is titlecase; false otherwise.

Since:

1.5

See Also:

isLowerCase(int) , isUpperCase(int) , toTitleCase(int) , getType(int)

isDigit

public static boolean isDigit(char ch)

Determines if the specified character is a digit.

A character is a digit if its general category type, provided 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

Many other character ranges contain digits as well.

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

Parameters:

ch - the character to be tested.

Returns:

true if the character is a digit; false otherwise.

See Also:

digit(char, int) , forDigit(int, int) , getType(char)

isDigit

 
public static boolean isDigit (int codePoint) 

Determines if the specified character (Unicode code point) is a digit.

A character is a digit if its general category type, provided 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

Many other character ranges contain digits as well.

Parameters:

codePoint - the character (Unicode code point) to be tested.

Returns:

true if the character is a digit; false otherwise.

Since:

1.5

See Also:

forDigit(int, int) , getType(int)

isDefined

public static boolean isDefined(char ch)

Determines if a character is defined in Unicode.

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

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

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

Parameters:

ch - the character to be tested

Returns:

true if the character has a defined meaning in Unicode; false otherwise.

Since:

1.0.2

See Also:

isDigit(char) , isLetter(char) , isLetterOrDigit(char) , isLowerCase(char) , isTitleCase(char) , isUpperCase(char)

isDefined

 
public static boolean isDefined (int codePoint) 

Determines if a character (Unicode code point) is defined in Unicode.

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

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

Parameters:

codePoint - the character (Unicode code point) to be tested.

Returns:

true if the character has a defined meaning in Unicode; false otherwise.

Since:

1.5

See Also:

isDigit(int) , isLetter(int) , isLetterOrDigit(int) , isLowerCase(int) , isTitleCase(int) , isUpperCase(int)

isLetter

public static boolean isLetter(char ch)

Determines if the specified character is a letter.

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

• UPPERCASE_LETTER
• LOWERCASE_LETTER
• TITLECASE_LETTER
• MODIFIER_LETTER
• OTHER_LETTER

Not all letters have case. Many characters are letters but are neither uppercase nor lowercase nor titlecase.

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

Parameters:

ch - the character to be tested.

Returns:

true if the character is a letter; false otherwise.

See Also:

isDigit(char) , isJavaIdentifierStart(char) , isJavaLetter(char) , isJavaLetterOrDigit(char) , isLetterOrDigit(char) , isLowerCase(char) , isTitleCase(char) , isUnicodeIdentifierStart(char) , isUpperCase(char)

isLetter

 
public static boolean isLetter (int codePoint) 

Determines if the specified character (Unicode code point) is a letter.

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

• UPPERCASE_LETTER
• LOWERCASE_LETTER
• TITLECASE_LETTER
• MODIFIER_LETTER
• OTHER_LETTER

Not all letters have case. Many characters are letters but are neither uppercase nor lowercase nor titlecase.

Parameters:

codePoint - the character (Unicode code point) to be tested.

Returns:

true if the character is a letter; false otherwise.

Since:

1.5

See Also:

isDigit(int) , isJavaIdentifierStart(int) , isLetterOrDigit(int) , isLowerCase(int) , isTitleCase(int) , isUnicodeIdentifierStart(int) , isUpperCase(int)

isLetterOrDigit

public static boolean isLetterOrDigit(char ch)

Determines if the specified character is a letter or digit.

A character is considered to be a letter or digit if 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.

Parameters:

ch - the character to be tested.

Returns:

true if the character is a letter or digit; false otherwise.

Since:

1.0.2

See Also:

isDigit(char) , isJavaIdentifierPart(char) , isJavaLetter(char) , isJavaLetterOrDigit(char) , isLetter(char) , isUnicodeIdentifierPart(char)

isLetterOrDigit

 
public static boolean isLetterOrDigit (int codePoint) 

Determines if the specified character (Unicode code point) is a letter or digit.

A character is considered to be a letter or digit if either isLetter(codePoint) or isDigit(codePoint) returns true for the character.

Parameters:

codePoint - the character (Unicode code point) to be tested.

Returns:

true if the character is a letter or digit; false otherwise.

Since:

1.5

See Also:

isDigit(int) , isJavaIdentifierPart(int) , isLetter(int) , isUnicodeIdentifierPart(int)

isJavaLetter

public static boolean isJavaLetter(char ch)

Deprecated.   Replaced by isJavaIdentifierStart(char).

Determines if the specified character is permissible as the first character in a Java identifier.

A character may start a Java identifier if and only if one of the following 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 "_").

Parameters:

ch - the character to be tested.

Returns:

true if the character may start a Java identifier; false otherwise.

Since:

1.02

See Also:

isJavaLetterOrDigit(char) , isJavaIdentifierStart(char) , isJavaIdentifierPart(char) , isLetter(char) , isLetterOrDigit(char) , isUnicodeIdentifierStart(char)

isJavaLetterOrDigit

public static boolean isJavaLetterOrDigit(char ch)

Deprecated.   Replaced by isJavaIdentifierPart(char).

Determines if the specified character may be part of a Java identifier as other than the first character.

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

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

Parameters:

ch - the character to be tested.

Returns:

true if the character may be part of a Java identifier; false otherwise.

Since:

1.02

See Also:

isJavaLetter(char) , isJavaIdentifierStart(char) , isJavaIdentifierPart(char) , isLetter(char) , isLetterOrDigit(char) , isUnicodeIdentifierPart(char) , isIdentifierIgnorable(char)

isJavaIdentifierStart

public static boolean isJavaIdentifierStart(char ch)

Determines if the specified character is permissible as the first character in a Java identifier.

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

• isLetter(ch) 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.

Parameters:

ch - the character to be tested.

Returns:

true if the character may start a Java identifier; false otherwise.

Since:

1.1

See Also:

isJavaIdentifierPart(char) , isLetter(char) , isUnicodeIdentifierStart(char)

isJavaIdentifierStart

 
public static boolean isJavaIdentifierStart (int codePoint) 

Determines if the character (Unicode code point) is permissible as the first character in a Java identifier.

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

• isLetter(codePoint) returns true
• getType(codePoint) returns LETTER_NUMBER
• the referenced character is a currency symbol (such as "$")
• the referenced character is a connecting punctuation character (such as "_").

Parameters:

codePoint - the character (Unicode code point) to be tested.

Returns:

true if the character may start a Java identifier; false otherwise.

Since:

1.5

See Also:

isJavaIdentifierPart(int) , isLetter(int) , isUnicodeIdentifierStart(int)

isJavaIdentifierPart

public static boolean isJavaIdentifierPart(char ch)

Determines if the specified character may be part of a Java identifier as other than the first character.

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

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

Parameters:

ch - the character to be tested.

Returns:

true if the character may be part of a Java identifier; false otherwise.

Since:

1.1

See Also:

isIdentifierIgnorable(char) , isJavaIdentifierStart(char) , isLetterOrDigit(char) , isUnicodeIdentifierPart(char)

isJavaIdentifierPart

 
public static boolean isJavaIdentifierPart (int codePoint) 

Determines if the character (Unicode code point) may be part of a Java identifier as other than the first character.

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

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

Parameters:

codePoint - the character (Unicode code point) to be tested.

Returns:

true if the character may be part of a Java identifier; false otherwise.

Since:

1.5

See Also:

isIdentifierIgnorable(int) , isJavaIdentifierStart(int) , isLetterOrDigit(int) , isUnicodeIdentifierPart(int)

isUnicodeIdentifierStart

public static boolean isUnicodeIdentifierStart(char ch)

Determines if the specified character is permissible as the first character in a Unicode identifier.

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

• 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.

Parameters:

ch - the character to be tested.

Returns:

true if the character may start a Unicode identifier; false otherwise.

Since:

1.1

See Also:

isJavaIdentifierStart(char) , isLetter(char) , isUnicodeIdentifierPart(char)