Java - Character Class

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Normally, when we work with characters, we use primitive data types char.

Example

char ch = 'a';

// Unicode for uppercase Greek omega character
char uniChar = '\u039A'; 

// an array of chars
char[] charArray ={ 'a', 'b', 'c', 'd', 'e' }; 

Use of Character Class in Java

However in development, we come across situations where we need to use objects instead of primitive data types. In order to achieve this, Java provides wrapper class Character for primitive data type char.

Java Character Class

The Character class offers a number of useful class (i.e., static) methods for manipulating characters. You can create a Character object with the Character constructor −

Character ch = new Character('a');

The Java compiler will also create a Character object for you under some circumstances. For example, if you pass a primitive char into a method that expects an object, the compiler automatically converts the char to a Character for you. This feature is called autoboxing or unboxing, if the conversion goes the other way.

Example of Java Character Class

// Here following primitive char 'a'
// is boxed into the Character object ch
Character ch = 'a';

// Here primitive 'x' is boxed for method test,
// return is unboxed to char 'c'
char c = test('x');

Escape Sequences

A character preceded by a backslash (\) is an escape sequence and has a special meaning to the compiler.

The newline character (\n) has been used frequently in this tutorial in System.out.println() statements to advance to the next line after the string is printed.

Following table shows the Java escape sequences −

When an escape sequence is encountered in a print statement, the compiler interprets it accordingly.

Example: Escape Sequences

If you want to put quotes within quotes, you must use the escape sequence, \", on the interior quotes −

public class Test {

   public static void main(String args[]) {
      System.out.println("She said \"Hello!\" to me.");
   }
}

Output

She said "Hello!" to me.

Character Class

Declaration

Following is the declaration for java.lang.Character class −

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

Field

Following are the fields for java.lang.Character class −

• static byte COMBINING_SPACING_MARK − This is the General category "Mc" in the Unicode specification.

• static byte CONNECTOR_PUNCTUATION − This is the General category "Pc" in the Unicode specification.

• static byte CONTROL − This is the General category "Cc" in the Unicode specification.

• static byte CURRENCY_SYMBOL − This is the General category "Sc" in the Unicode specification.

• static byte DASH_PUNCTUATION − This is the General category "Pd" in the Unicode specification.

• static byte DECIMAL_DIGIT_NUMBER − This is the General category "Nd" in the Unicode specification.

• static byte DIRECTIONALITY_ARABIC_NUMBER − This is the Weak bidirectional character type "AN" in the Unicode specification.

• static byte DIRECTIONALITY_BOUNDARY_NEUTRAL − This is the Weak bidirectional character type "BN" in the Unicode specification.

• static byte DIRECTIONALITY_COMMON_NUMBER_SEPARATOR − This is the Weak bidirectional character type "CS" in the Unicode specification.

• static byte DIRECTIONALITY_EUROPEAN_NUMBER − This is the Weak bidirectional character type "EN" in the Unicode specification.

• static byte DIRECTIONALITY_EUROPEAN_NUMBER_SEPARATOR − This is the Weak bidirectional character type "ES" in the Unicode specification.

• static byte DIRECTIONALITY_EUROPEAN_NUMBER_TERMINATOR − This is the Weak bidirectional character type "ET" in the Unicode specification.

• static byte DIRECTIONALITY_LEFT_TO_RIGHT − This is the Strong bidirectional character type "L" in the Unicode specification.

• static byte DIRECTIONALITY_LEFT_TO_RIGHT_EMBEDDING − This is the Strong bidirectional character type "LRE" in the Unicode specification.

• static byte DIRECTIONALITY_LEFT_TO_RIGHT_OVERRIDE − This is the Strong bidirectional character type "LRO" in the Unicode specification.

• static byte DIRECTIONALITY_NONSPACING_MARK − This is the Weak bidirectional character type "NSM" in the Unicode specification.

• static byte DIRECTIONALITY_OTHER_NEUTRALS − This is the Neutral bidirectional character type "ON" in the Unicode specification.

• static byte DIRECTIONALITY_PARAGRAPH_SEPARATOR − This is the Neutral bidirectional character type "B" in the Unicode specification.

• static byte DIRECTIONALITY_POP_DIRECTIONAL_FORMAT − This is the Weak bidirectional character type "PDF" in the Unicode specification.

• static byte DIRECTIONALITY_RIGHT_TO_LEFT − This is the Strong bidirectional character type "R" in the Unicode specification.

• static byte DIRECTIONALITY_RIGHT_TO_LEFT_ARABIC − This is the Strong bidirectional character type "AL" in the Unicode specification.

• static byte DIRECTIONALITY_RIGHT_TO_LEFT_EMBEDDING − This is the Strong bidirectional character type "RLE" in the Unicode specification.

• static byte DIRECTIONALITY_RIGHT_TO_LEFT_OVERRIDE − This is the Strong bidirectional character type "RLO" in the Unicode specification.

• static byte DIRECTIONALITY_SEGMENT_SEPARATOR − This is the Neutral bidirectional character type "S" in the Unicode specification.

• static byte DIRECTIONALITY_UNDEFINED − This is the Undefined bidirectional character type.

• static byte DIRECTIONALITY_WHITESPACE − This is the Neutral bidirectional character type "WS" in the Unicode specification.

• static byte ENCLOSING_MARK − This is the General category "Me" in the Unicode specification.

• static byte END_PUNCTUATION − This is the General category "Pe" in the Unicode specification.

• static byte FINAL_QUOTE_PUNCTUATION − This is the General category "Pf" in the Unicode specification.

• static byte FORMAT − This is the General category "Cf" in the Unicode specification.

• static byte INITIAL_QUOTE_PUNCTUATION − This is the General category "Pi" in the Unicode specification.

• static byte LETTER_NUMBER − This is the General category "Nl" in the Unicode specification.

• static byte LINE_SEPARATOR − This is the General category "Zl" in the Unicode specification.

• static byte LOWERCASE_LETTER − This is the General category "Ll" in the Unicode specification.

• static byte MATH_SYMBOL − This is the General category "Sm" in the Unicode specification.

• static int MAX_CODE_POINT − This is the maximum value of a Unicode code point.

• static char MAX_HIGH_SURROGATE − This is the maximum value of a Unicode high-surrogate code unit in the UTF-16 encoding.

• static char MAX_LOW_SURROGATE − This is the maximum value of a Unicode low-surrogate code unit in the UTF-16 encoding.

• static int MAX_RADIX − This is the maximum radix available for conversion to and from strings.

• static char MAX_SURROGATE − This is the maximum value of a Unicode surrogate code unit in the UTF-16 encoding.

• static char MAX_VALUE − This is the constant value of this field is the largest value of type char, '\uFFFF'.

• static int MIN_CODE_POINT − This is the minimum value of a Unicode code poin

• static char MIN_HIGH_SURROGATE − This is the minimum value of a Unicode high-surrogate code unit in the UTF-16 encoding.

• static char MIN_LOW_SURROGATE − This is the minimum value of a Unicode low-surrogate code unit in the UTF-16 encoding.

• static int MIN_RADIX − This is the minimum radix available for conversion to and from strings.

• static int MIN_SUPPLEMENTARY_CODE_POINT − This is the minimum value of a supplementary code point.

• static char MIN_SURROGATE − This is the minimum value of a Unicode surrogate code unit in the UTF-16 encoding.

• static char MIN_VALUE − This is the constant value of this field is the smallest value of type char, '\u0000'.

• static byte MODIFIER_LETTER − This is the General category "Lm" in the Unicode specification.

• static byte MODIFIER_SYMBOL − This is the General category "Sk" in the Unicode specification.

• static byte NON_SPACING_MARK − This is the General category "Mn" in the Unicode specification.

• static byte OTHER_LETTER − This is the General category "Lo" in the Unicode specification.

• static byte OTHER_NUMBER − This is the General category "No" in the Unicode specification.

• static byte OTHER_PUNCTUATION − This is the General category "Po" in the Unicode specification.

• static byte OTHER_SYMBOL − This is the General category "So" in the Unicode specification.

• static byte PARAGRAPH_SEPARATOR − This is the General category "Zp" in the Unicode specification.

• static byte PRIVATE_USE − This is the General category "Co" in the Unicode specification.

• static int SIZE − This is the number of bits used to represent a char value in unsigned binary form.

• static byte SPACE_SEPARATOR − This is the General category "Zs" in the Unicode specification.

• static byte START_PUNCTUATION − This is the General category "Ps" in the Unicode specification.

• static byte SURROGATE − This is the General category "Cs" in the Unicode specification.

• static byte TITLECASE_LETTER − This is the General category "Lt" in the Unicode specification.

• static Class<Character> TYPE − This is the Class instance representing the primitive type char.

• static byte UNASSIGNED − This is the General category "Cn" in the Unicode specification.

• static byte UPPERCASE_LETTER − This is the General category "Lu" in the Unicode specification.

Class constructors

Class methods

Methods inherited

This class inherits methods from the following classes −

• java.lang.Object

Example

The following example shows the usage of Java Character charCount() method. In this program, we've created a int variable and assigned it a Hexadecimal value equivalent to a char value. Then using charCount() method, we've checked if it is a valid supplementary character or not. Then result is printed.

package com.tutorialspoint;

public class CharacterDemo {
   public static void main(String[] args) {

      // create and assign values to int codepoint cp
      int cp = 0x12345;

      // create an int res
      int res;

      // assign the result of charCount on cp to res
      res = Character.charCount(cp);
      String str1 = "It is not a valid supplementary character";
      String str2 = "It is a valid supplementary character";

      // print res value
      if ( res == 1 ) {
         System.out.println( str1 );
      } else if ( res == 2 ) {
         System.out.println( str2 );
      }
   }
}

Output

Let us compile and run the above program, this will produce the following result −

It is a valid supplementary character