Class Character

  java.lang.Character

All Implemented Interfaces:

Serializable, Comparable<Character>, Constable

1.0

Lee Boynton, Guy Steele, Akira Tanaka, Martin Buchholz, Ulf Zibis

Field Detail

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 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 constant value of this field is the smallest value of type char, '\u0000'. See Also:

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

The Class instance representing the primitive type char.

General category "Cn" in the Unicode specification. See Also:

General category "Lu" in the Unicode specification. See Also:

General category "Ll" in the Unicode specification. See Also:

General category "Lt" in the Unicode specification. See Also:

General category "Lm" in the Unicode specification. See Also:

General category "Lo" in the Unicode specification. See Also:

General category "Mn" in the Unicode specification. See Also:

General category "Me" in the Unicode specification. See Also:

General category "Mc" in the Unicode specification. See Also:

General category "Nd" in the Unicode specification. See Also:

General category "Nl" in the Unicode specification. See Also:

General category "No" in the Unicode specification. See Also:

General category "Zs" in the Unicode specification. See Also:

General category "Zl" in the Unicode specification. See Also:

General category "Zp" in the Unicode specification. See Also:

General category "Cc" in the Unicode specification. See Also:

General category "Cf" in the Unicode specification. See Also:

General category "Co" in the Unicode specification. See Also:

General category "Cs" in the Unicode specification. See Also:

General category "Pd" in the Unicode specification. See Also:

General category "Ps" in the Unicode specification. See Also:

General category "Pe" in the Unicode specification. See Also:

General category "Pc" in the Unicode specification. See Also:

General category "Po" in the Unicode specification. See Also:

General category "Sm" in the Unicode specification. See Also:

General category "Sc" in the Unicode specification. See Also:

General category "Sk" in the Unicode specification. See Also:

General category "So" in the Unicode specification. See Also:

General category "Pi" in the Unicode specification. See Also:

General category "Pf" in the Unicode specification. See Also:

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

Strong bidirectional character type "L" in the Unicode specification. See Also:

Strong bidirectional character type "R" in the Unicode specification. See Also:

Strong bidirectional character type "AL" in the Unicode specification. See Also:

Weak bidirectional character type "EN" in the Unicode specification. See Also:

Weak bidirectional character type "ES" in the Unicode specification. See Also:

Weak bidirectional character type "ET" in the Unicode specification. See Also:

Weak bidirectional character type "AN" in the Unicode specification. See Also:

Weak bidirectional character type "CS" in the Unicode specification. See Also:

Weak bidirectional character type "NSM" in the Unicode specification. See Also:

Weak bidirectional character type "BN" in the Unicode specification. See Also:

Neutral bidirectional character type "B" in the Unicode specification. See Also:

Neutral bidirectional character type "S" in the Unicode specification. See Also:

Neutral bidirectional character type "WS" in the Unicode specification. See Also:

Neutral bidirectional character type "ON" in the Unicode specification. See Also:

Strong bidirectional character type "LRE" in the Unicode specification. See Also:

Strong bidirectional character type "LRO" in the Unicode specification. See Also:

Strong bidirectional character type "RLE" in the Unicode specification. See Also:

Strong bidirectional character type "RLO" in the Unicode specification. See Also:

Weak bidirectional character type "PDF" in the Unicode specification. See Also:

Weak bidirectional character type "LRI" in the Unicode specification. See Also:

Weak bidirectional character type "RLI" in the Unicode specification. See Also:

Weak bidirectional character type "FSI" in the Unicode specification. See Also:

Weak bidirectional character type "PDI" in the Unicode specification. See Also:

The minimum value of a Unicode high-surrogate code unit in the UTF-16 encoding, constant '\uD800'. A high-surrogate is also known as a leading-surrogate. See Also:

The maximum value of a Unicode high-surrogate code unit in the UTF-16 encoding, constant '\uDBFF'. A high-surrogate is also known as a leading-surrogate. See Also:

The minimum value of a Unicode low-surrogate code unit in the UTF-16 encoding, constant '\uDC00'. A low-surrogate is also known as a trailing-surrogate. See Also:

The maximum value of a Unicode low-surrogate code unit in the UTF-16 encoding, constant '\uDFFF'. A low-surrogate is also known as a trailing-surrogate. See Also:

The minimum value of a Unicode surrogate code unit in the UTF-16 encoding, constant '\uD800'. See Also:

The maximum value of a Unicode surrogate code unit in the UTF-16 encoding, constant '\uDFFF'. See Also:

The minimum value of a Unicode supplementary code point, constant U+10000. See Also:

The minimum value of a Unicode code point, constant U+0000. See Also:

The maximum value of a Unicode code point, constant U+10FFFF. See Also:

The number of bits used to represent a char value in unsigned binary form, constant 16. See Also:

The number of bytes used to represent a char value in unsigned binary form. See Also:

Constructor Detail

Deprecated, for removal. It is rarely appropriate to use this constructor. The static factory valueOf(char) is generally a better choice, as it is likely to yield significantly better space and time performance.

Method Detail

Returns an Optional containing the nominal descriptor for this instance. Returns: Since:

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. This method will always cache values in the range '\u0000' to '\u007F', inclusive, and may cache other values outside of this range. Returns: Since:

Returns the value of this Character object.

Returns a hash code for this Character; equal to the result of invoking charValue(). Returns: See Also:

Returns a hash code for a char value; compatible with Character.hashCode(). Returns: Since:

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. Parameters: Returns: See Also:

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. Returns:

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

Returns a String object representing the specified character (Unicode code point). The result is a string of length 1 or 2, consisting solely of the specified codePoint. Returns: Throws: Since:

Determines whether the specified code point is a valid Unicode code point value. Returns: Since:

Determines whether the specified character (Unicode code point) is in the Basic Multilingual Plane (BMP). Such code points can be represented using a single char. Returns: Since:

Determines whether the specified character (Unicode code point) is in the supplementary character range. Returns: Since:

Determines if the given char value is a Unicode high-surrogate code unit (also known as leading-surrogate code unit).

Such values do not represent characters by themselves, but are used in the representation of supplementary characters in the UTF-16 encoding.

Returns: Since: See Also:

Determines if the given char value is a Unicode low-surrogate code unit (also known as trailing-surrogate code unit).

Such values do not represent characters by themselves, but are used in the representation of supplementary characters in the UTF-16 encoding.

Returns: Since: See Also:

Determines if the given char value is a Unicode surrogate code unit.

Such values do not represent characters by themselves, but are used in the representation of supplementary characters in the UTF-16 encoding.

A char value is a surrogate code unit if and only if it is either a low-surrogate code unit or a high-surrogate code unit.

Returns: Since:

Determines whether the specified pair of char values is a valid Unicode surrogate pair.

This method is equivalent to the expression:

 isHighSurrogate(high) && isLowSurrogate(low)
 

Returns: Since:

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.

Returns: Since: See Also:

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. Returns: Since:

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. Returns: Throws: Since:

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. Returns: Throws: Since:

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. Returns: Throws: Since:

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. Returns: Throws: Since:

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. Returns: Throws: Since:

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. Returns: Throws: Since:

Returns the leading surrogate (a high surrogate code unit) of the surrogate pair representing the specified supplementary character (Unicode code point) in the UTF-16 encoding. If the specified character is not a supplementary character, an unspecified char is returned.

If isSupplementaryCodePoint(x) is true, then isHighSurrogate(highSurrogate(x)) and toCodePoint(highSurrogate(x), lowSurrogate(x)) == x are also always true.

Returns: Since:

Returns the trailing surrogate (a low surrogate code unit) of the surrogate pair representing the specified supplementary character (Unicode code point) in the UTF-16 encoding. If the specified character is not a supplementary character, an unspecified char is returned.

If isSupplementaryCodePoint(x) is true, then isLowSurrogate(lowSurrogate(x)) and toCodePoint(highSurrogate(x), lowSurrogate(x)) == x are also always true.

Returns: Since:

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. Returns: Throws: Since:

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. Returns: Throws: Since:

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 chars) of the text range is endIndex-beginIndex. Unpaired surrogates within the text range count as one code point each. Returns: Throws: Since:

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 chars. Unpaired surrogates within the subarray count as one code point each. Returns: Throws: Since:

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. Returns: Throws: Since:

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. Returns: Throws: Since:

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, or it has contributory property Other_Lowercase as defined by the Unicode Standard.

The following are examples of lowercase characters:

 a b c d e f g h i j k l m n o p q r s t u v w x y z
 '\u00DF' '\u00E0' '\u00E1' '\u00E2' '\u00E3' '\u00E4' '\u00E5' '\u00E6'
 '\u00E7' '\u00E8' '\u00E9' '\u00EA' '\u00EB' '\u00EC' '\u00ED' '\u00EE'
 '\u00EF' '\u00F0' '\u00F1' '\u00F2' '\u00F3' '\u00F4' '\u00F5' '\u00F6'
 '\u00F8' '\u00F9' '\u00FA' '\u00FB' '\u00FC' '\u00FD' '\u00FE' '\u00FF'
 

Many other Unicode characters are lowercase too.

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

Returns: See Also:

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, or it has contributory property Other_Lowercase as defined by the Unicode Standard.

The following are examples of lowercase characters:

 a b c d e f g h i j k l m n o p q r s t u v w x y z
 '\u00DF' '\u00E0' '\u00E1' '\u00E2' '\u00E3' '\u00E4' '\u00E5' '\u00E6'
 '\u00E7' '\u00E8' '\u00E9' '\u00EA' '\u00EB' '\u00EC' '\u00ED' '\u00EE'
 '\u00EF' '\u00F0' '\u00F1' '\u00F2' '\u00F3' '\u00F4' '\u00F5' '\u00F6'
 '\u00F8' '\u00F9' '\u00FA' '\u00FB' '\u00FC' '\u00FD' '\u00FE' '\u00FF'
 

Many other Unicode characters are lowercase too.

Returns: Since: See Also:

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. or it has contributory property Other_Uppercase as defined by the Unicode Standard.

The following are examples of uppercase characters:

 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
 '\u00C0' '\u00C1' '\u00C2' '\u00C3' '\u00C4' '\u00C5' '\u00C6' '\u00C7'
 '\u00C8' '\u00C9' '\u00CA' '\u00CB' '\u00CC' '\u00CD' '\u00CE' '\u00CF'
 '\u00D0' '\u00D1' '\u00D2' '\u00D3' '\u00D4' '\u00D5' '\u00D6' '\u00D8'
 '\u00D9' '\u00DA' '\u00DB' '\u00DC' '\u00DD' '\u00DE'
 

Many other Unicode characters are uppercase too.

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

Returns: Since: See Also:

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, or it has contributory property Other_Uppercase as defined by the Unicode Standard.

The following are examples of uppercase characters:

 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
 '\u00C0' '\u00C1' '\u00C2' '\u00C3' '\u00C4' '\u00C5' '\u00C6' '\u00C7'
 '\u00C8' '\u00C9' '\u00CA' '\u00CB' '\u00CC' '\u00CD' '\u00CE' '\u00CF'
 '\u00D0' '\u00D1' '\u00D2' '\u00D3' '\u00D4' '\u00D5' '\u00D6' '\u00D8'
 '\u00D9' '\u00DA' '\u00DB' '\u00DC' '\u00DD' '\u00DE'
 

Many other Unicode characters are uppercase too.

Returns: Since: See Also:

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.

Returns: Since: See Also:

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.

Returns: Since: See Also:

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.

Returns: See Also:

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. Returns: Since: See Also:

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.

Returns: Since: See Also:

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.

Returns: Since: See Also:

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.

Returns: See Also:

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. Returns: Since: See Also:

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.

Returns: Since: See Also:

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.

Returns: Since: See Also:

@Deprecated("1.1")

Deprecated. Replaced by isJavaIdentifierStart(char). Returns: Since: See Also:

@Deprecated("1.1")

Deprecated. Replaced by isJavaIdentifierPart(char). Returns: Since: See Also:

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

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

• UPPERCASE_LETTER
• LOWERCASE_LETTER
• TITLECASE_LETTER
• MODIFIER_LETTER
• OTHER_LETTER
• LETTER_NUMBER

or it has contributory property Other_Alphabetic as defined by the Unicode Standard. Returns: Since:

Determines if the specified character (Unicode code point) is a CJKV (Chinese, Japanese, Korean and Vietnamese) ideograph, as defined by the Unicode Standard. Returns: Since:

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.

Returns: Since: See Also:

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 '_').

Returns: Since: See Also:

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

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

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

Returns: Since: See Also:

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

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

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

Returns: Since: See Also:

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.
• it is an Other_ID_Start character.

This method conforms to UAX31-R1: Default Identifiers requirement of the Unicode Standard, with the following profile of UAX31:

 Start := ID_Start + 'VERTICAL TILDE' (U+2E2F)
 

'VERTICAL TILDE' is added to Start for backward compatibility.

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

Returns: Since: See Also:

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.
• it is an Other_ID_Start character.

This method conforms to UAX31-R1: Default Identifiers requirement of the Unicode Standard, with the following profile of UAX31:

 Start := ID_Start + 'VERTICAL TILDE' (U+2E2F)
 

'VERTICAL TILDE' is added to Start for backward compatibility. Returns: Since: See Also:

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

A character may be part of a Unicode identifier if and only if one of the following statements is true:

• it is a letter
• it is a connecting punctuation character (such as '_')
• it is a digit
• it is a numeric letter (such as a Roman numeral character)
• it is a combining mark
• it is a non-spacing mark
• isIdentifierIgnorable returns true for this character.
• it is an Other_ID_Start character.
• it is an Other_ID_Continue character.

This method conforms to UAX31-R1: Default Identifiers requirement of the Unicode Standard, with the following profile of UAX31:

 Continue := Start + ID_Continue + ignorable
 Medial := empty
 ignorable := isIdentifierIgnorable(char) returns true for the character
 

ignorable is added to Continue for backward compatibility.

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

Returns: Since: See Also:

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

A character may be part of a Unicode identifier if and only if one of the following statements is true:

• it is a letter
• it is a connecting punctuation character (such as '_')
• it is a digit
• it is a numeric letter (such as a Roman numeral character)
• it is a combining mark
• it is a non-spacing mark
• isIdentifierIgnorable returns true for this character.
• it is an Other_ID_Start character.
• it is an Other_ID_Continue character.

This method conforms to UAX31-R1: Default Identifiers requirement of the Unicode Standard, with the following profile of UAX31:

 Continue := Start + ID_Continue + ignorable
 Medial := empty
 ignorable := isIdentifierIgnorable(int) returns true for the character
 

ignorable is added to Continue for backward compatibility. Returns: Since: See Also:

Determines if the specified character should be regarded as an ignorable character in a Java identifier or a Unicode identifier.

The following Unicode characters are ignorable in a Java identifier or a Unicode identifier:

• ISO control characters that are not whitespace
  • '\u0000' through '\u0008'
  • '\u000E' through '\u001B'
  • '\u007F' through '\u009F'
• all characters that have the FORMAT general category value

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

Returns: Since: See Also:

Determines if the specified character (Unicode code point) should be regarded as an ignorable character in a Java identifier or a Unicode identifier.

The following Unicode characters are ignorable in a Java identifier or a Unicode identifier:

• ISO control characters that are not whitespace
  • '\u0000' through '\u0008'
  • '\u000E' through '\u001B'
  • '\u007F' through '\u009F'
• all characters that have the FORMAT general category value

Returns: Since: See Also:

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, String.toLowerCase() should be used to map characters to lowercase. String case mapping methods have several benefits over Character case mapping methods. String case mapping methods can perform locale-sensitive mappings, context-sensitive mappings, and 1:M character mappings, whereas the Character case mapping methods cannot.

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

Returns: See Also:

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, String.toLowerCase() should be used to map characters to lowercase. String case mapping methods have several benefits over Character case mapping methods. String case mapping methods can perform locale-sensitive mappings, context-sensitive mappings, and 1:M character mappings, whereas the Character case mapping methods cannot.

Returns: Since: See Also:

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, String.toUpperCase() should be used to map characters to uppercase. String case mapping methods have several benefits over Character case mapping methods. String case mapping methods can perform locale-sensitive mappings, context-sensitive mappings, and 1:M character mappings, whereas the Character case mapping methods cannot.

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

Returns: See Also:

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, String.toUpperCase() should be used to map characters to uppercase. String case mapping methods have several benefits over Character case mapping methods. String case mapping methods can perform locale-sensitive mappings, context-sensitive mappings, and 1:M character mappings, whereas the Character case mapping methods cannot.

Returns: Since: See Also:

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.

Returns: Since: See Also:

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.

Returns: Since: See Also:

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:

• The method 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.
• The character is one of the uppercase Latin letters 'A' through 'Z' and its code is less than radix + 'A' - 10. In this case, ch - 'A' + 10 is returned.
• The character is one of the lowercase Latin letters 'a' through 'z' and its code is less than radix + 'a' - 10. In this case, ch - 'a' + 10 is returned.
• The character is one of the fullwidth uppercase Latin letters A ('\uFF21') through Z ('\uFF3A') and its code is less than radix + '\uFF21' - 10. In this case, ch - '\uFF21' + 10 is returned.
• The character is one of the fullwidth lowercase Latin letters a ('\uFF41') through z ('\uFF5A') and its code is less than radix + '\uFF41' - 10. In this case, ch - '\uFF41' + 10 is returned.

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

Returns: See Also:

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:

• The method 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.
• The character is one of the uppercase Latin letters 'A' through 'Z' and its code is less than radix + 'A' - 10. In this case, codePoint - 'A' + 10 is returned.
• The character is one of the lowercase Latin letters 'a' through 'z' and its code is less than radix + 'a' - 10. In this case, codePoint - 'a' + 10 is returned.
• The character is one of the fullwidth uppercase Latin letters A ('\uFF21') through Z ('\uFF3A') and its code is less than radix + '\uFF21' - 10. In this case, codePoint - '\uFF21' + 10 is returned.
• The character is one of the fullwidth lowercase Latin letters a ('\uFF41') through z ('\uFF5A') and its code is less than radix + '\uFF41'- 10. In this case, codePoint - '\uFF41' + 10 is returned.

Returns: Since: See Also:

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.

Returns: Since: See Also:

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.

Returns: Since: See Also:

@Deprecated("1.1")

Deprecated. Replaced by isWhitespace(char). Returns: See Also:

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.

Returns: Since: See Also:

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:

• SPACE_SEPARATOR
• LINE_SEPARATOR
• PARAGRAPH_SEPARATOR

Returns: Since: See Also:

Determines if the specified character is white space according to Java. A character is a Java whitespace character if and only if it satisfies one of the following criteria:

• It is a Unicode space character (SPACE_SEPARATOR, LINE_SEPARATOR, or PARAGRAPH_SEPARATOR) but is not also a non-breaking space ('\u00A0', '\u2007', '\u202F').
• It is '\t', U+0009 HORIZONTAL TABULATION.
• It is '\n', U+000A LINE FEED.
• It is '\u000B', U+000B VERTICAL TABULATION.
• It is '\f', U+000C FORM FEED.
• It is '\r', U+000D CARRIAGE RETURN.
• It is '\u001C', U+001C FILE SEPARATOR.
• It is '\u001D', U+001D GROUP SEPARATOR.
• It is '\u001E', U+001E RECORD SEPARATOR.
• It is '\u001F', U+001F UNIT SEPARATOR.

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

Returns: Since: See Also:

Determines if the specified character (Unicode code point) is white space according to Java. A character is a Java whitespace character if and only if it satisfies one of the following criteria:

• It is a Unicode space character (SPACE_SEPARATOR, LINE_SEPARATOR, or PARAGRAPH_SEPARATOR) but is not also a non-breaking space ('\u00A0', '\u2007', '\u202F').
• It is '\t', U+0009 HORIZONTAL TABULATION.
• It is '\n', U+000A LINE FEED.
• It is '\u000B', U+000B VERTICAL TABULATION.
• It is '\f', U+000C FORM FEED.
• It is '\r', U+000D CARRIAGE RETURN.
• It is '\u001C', U+001C FILE SEPARATOR.
• It is '\u001D', U+001D GROUP SEPARATOR.
• It is '\u001E', U+001E RECORD SEPARATOR.
• It is '\u001F', U+001F UNIT SEPARATOR.

Returns: Since: See Also:

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.

Returns: Since: See Also:

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'. Returns: Since: See Also:

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.

Returns: Since: See Also:

Returns a value indicating a character's general category. Returns: Since: See Also:

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.

Returns: See Also:

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.

Returns: Since: See Also:

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. Returns: Since: See Also:

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.

Returns: Since:

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. Returns: Since:

Compares two Character objects numerically. Parameters: Returns: Since:

Compares two char values numerically. The value returned is identical to what would be returned by:

    Character.valueOf(x).compareTo(Character.valueOf(y))
 

Returns: Since:

Returns the value obtained by reversing the order of the bytes in the specified char value. Returns: Since:

Returns the Unicode name of the specified character codePoint, or null if the code point is unassigned.

Note: if the specified character is not assigned a name by the UnicodeData file (part of the Unicode Character Database maintained by the Unicode Consortium), the returned name is the same as the result of expression:

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

Returns: Throws: Since:

Returns the code point value of the Unicode character specified by the given Unicode character name.

Note: if a character is not assigned a name by the UnicodeData file (part of the Unicode Character Database maintained by the Unicode Consortium), its name is defined as the result of expression:

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

The name matching is case insensitive, with any leading and trailing whitespace character removed.

Returns: Throws: Since:

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