Character Class in Java - Methods | Set 2

In Java, the Character Class wraps the value of a primitive data type char into an object of datatype Character. This object contains a single field having the data type char. This class provides several methods regarding character manipulations, like converting them from lowercase to uppercase. Character Class is based on Unicode Standards to provide character information.

Features of Character Class:

The key features of the character class in Java are listed below:

• It wraps a primitive char value in an object.
• It checks character properties like mirroring and alphabetic status.
• It supports Unicode code point validation
• It also enables byte reversal for characters.
  

Example: Using the toUpperCase method of the Character class to transform the character to uppercase.

Upper case of 'g' is 'G'

Declaration of Character Class

The declaration of character class is listed below:

public final class Character extends Object implements Serializable, Comparable<Character>

Note: The Character class is final that's why it cannot be subclassed.

Java Character Methods

The table below demonstrates the character class methods.

Note: Refer to this article Character Class set 1 Methods for set 1 methods.

Now, we are going to discuss about each method one by one in detail:

1. toUpperCase(): This method converts the given character in the argument to its uppercase based on Unicode values.

Syntax:

public static char toUpperCase(char ch)

• Parameter: It takes single character ch which is converted to upper case.
• Return Type: This method returns character of the argumented character in the uppercase.

2. toLowerCase(): This method converts given character in argument to its Lower case based on Unicode values.

Syntax:

public static char toLowerCase(char ch)

• Parameter: This method takes a character(ch) to be converted to Lower case
• Return Type: This method returns the character in Lower case character of the argumented character.

3. isMirrored(): This method checks whether passed argument is mirrored or not, based on Unicode values. 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. e.g. : [ ] { } ( )

Syntax:

public static boolean isMirrored(char ch)

• Parameter: This method takes a character ch
• Return Type: This method returns a boolean value if char 'ch' is mirrored, else false.

Example: Java code explaining use of toUpperCase(), toLowerCase(), isMirrored() methods of Character Class.

Upper value for g : G
Upper value for O : O

Lower value for G : g
Lower value for O : o

Checking - : false
Checking ) : true
Checking { : true
Checking ] : true

4. reverseBytes(): This method returns a character by reversing the order of bytes in the argumented character.

Syntax:

public static char reverseBytes(char ch)

• Parameter: This method takes a single parameter a char (ch) whose bytes need to be reverse.
• Return Type: This method returns a new char value with the reversed value of the given char.

5. isAlphabetic(int CodePoint): This method is used to check whether the specified Unicode codePoint represents an alphabetic character.

Syntax:

public static boolean isAlphabetic(int codePoint)

• Parameter: This method takes a single int value codePoint the unicode value need to check.
• Return Type: It returns a boolean true if the code point is alphabetic or return false.

Example: Java code demonstrates the use of isValidCodePoint(), reverseBytes(), isAlphabetic() methods.