java.lang
Class Character

java.lang.Object
  |
  +--java.lang.Character

public final class Character

extends Object

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 the type of a character and converting characters from uppercase to lowercase and vice versa.

Many of the methods of class Character are defined in terms of a "Unicode attribute table" that specifies a name for every defined Unicode code point. The table also includes other attributes, such as a decimal value, an uppercase equivalent, a lowercase equivalent, and/or a titlecase equivalent. The Unicode attribute table is available on the World Wide Web as the file:

ftp://unicode.org/pub/MappingTables/UnicodeData1.1.5.txt

For a more detailed specification of the Character class, one that encompasses the exact behavior of methods such as isDigit, isLetter, isLowerCase, and isUpperCase over the full range of Unicode values, see Gosling, Joy, and Steele, The Java Language Specification.

Since:

JDK1.0

Field Summary

static int	MAX_RADIX The maximum radix available for conversion to and from Strings.
static char	MAX_VALUE The constant value of this field is the largest value of type char.
static int	MIN_RADIX The minimum radix available for conversion to and from Strings.
static char	MIN_VALUE The constant value of this field is the smallest value of type char.

Constructor Summary

Character(char Value)
Constructs a Character object and initializes it so that it represents the primitive value argument.

Method Summary

char	charValue() Returns the value of this Character object.
static int	digit(char ch, int radix) Returns the numeric value of the character ch in the specified radix.
boolean	equals(Object obj) Compares this object against the specified object.
int	hashCode() Returns a hash code for this Character.
static boolean	isDigit(char ch) Determines if the specified character is a digit.
static boolean	isLowerCase(char ch) Determines if the specified character is a lowercase character.
static boolean	isUpperCase(char ch) Determines if the specified character is an uppercase character.
static char	toLowerCase(char ch) The given character is mapped to its lowercase equivalent; if the character has no lowercase equivalent, the character itself is returned.
String	toString() Returns a String object representing this character's value.
static char	toUpperCase(char ch) Converts the character argument to uppercase.

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

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:

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:

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.

Since:

JDK1.0.2

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.

Since:

JDK1.0.2

See Also:

Constant Field Values

Constructor Detail

Character

public Character(char Value)

Constructs a Character object and initializes it so that it represents the primitive value argument.

Since:

JDK1.0

Method Detail

charValue

public char charValue()

Returns the value of this Character object.

Returns:

the primitive char value represented by this object.

Since:

JDK1.0

hashCode

public int hashCode()

Returns a hash code for this Character.

Overrides:

hashCode in class Object

Returns:

a hash code value for this object.

Since:

JDK1.0

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.

Since:

JDK1.0

See Also:

Hashtable

toString

public String toString()

Returns a String object representing this character's value. Converts this Character object to a string. The result is a string whose length is 1. The string's sole component is the primitive char value represented by this object.

Overrides:

toString in class Object

Returns:

a string representation of this object.

Since:

JDK1.0

toLowerCase

public static char toLowerCase(char ch)

The given character is mapped to its lowercase equivalent; if the character has no lowercase equivalent, the character itself is returned.

Parameters:

ch - the character to be converted.

Returns:

the lowercase equivalent of the character, if any; otherwise the character itself.

Since:

JDK1.0

See Also:

toUpperCase(char)

toUpperCase

public static char toUpperCase(char ch)

Converts the character argument to uppercase.

Parameters:

ch - the character to be converted.

Returns:

the uppercase equivalent of the character, if any; otherwise the character itself.

Since:

JDK1.0

See Also:

toLowerCase(char)

isDigit

public static boolean isDigit(char ch)

Determines if the specified character is a digit. This is currently only supported for ISO-LATIN-1 digits: "0" through "9".

Parameters:

ch - the character to be tested.

Returns:

true if the character is a digit; false otherwise.

Since:

JDK1.0

digit

public static int digit(char ch,
                        int radix)

Returns the numeric value of the character ch in the specified radix. This is only supported for ISO-LATIN-1 characters.

Parameters:

ch - the character to be converted.

radix - the radix.

Returns:

the numeric value represented by the character in the specified radix.

Since:

JDK1.0

See Also:

isDigit(char)

isLowerCase

public static boolean isLowerCase(char ch)

Determines if the specified character is a lowercase character. This is currently only supported for ISO-LATIN-1 characters: "a" through "z".

Parameters:

ch - the character to be tested.

Returns:

true if the character is lowercase; false otherwise.

Since:

JDK1.0

See Also:

isLowerCase(char), toLowerCase(char)

isUpperCase

public static boolean isUpperCase(char ch)

Determines if the specified character is an uppercase character. This is currently only supported for ISO-LATIN-1 characters: "A" through "Z".

Parameters:

ch - the character to be tested.

Returns:

true if the character is uppercase; false otherwise.

Since:

1.0

See Also:

isLowerCase(char), toUpperCase(char)