Java Character class

The Character class generally wraps the value of all the primitive type char into an object. Any object of the type Character may contain a single field whose type is char.

All the fields, methods, and constructors of the class Character are specified by the Unicode Data file which is particularly a part of Unicode Character Database and is maintained by the Unicode Consortium.

A set of characters ranging from U+0000 to U+FFFF is sometimes known as the Basic Multilingual Plane(i.e. BMP). The characters whose codePoints are greater than U+FFFF are known as supplementary characters. The Java language generally uses the UTF-16 encoding method to represent the char arrays in String or String Buffer. In this type of representation, the supplementary characters are represented as a pair of characters, the first which is from the high-surrogate range(\uD800-\uDBFF) and the second which is from the low-surrogate range(\uDc00-\uDBFF).

Java Character class Methods

Method	Description
charCount(int codePoint)	Determines the number of char values which are required to represent the given character.
charValue()	Returns the value of the given Character object.
codePointAt(char[]a, int index)	Returns the codePoint for the specified index of the given array.
codePointAt(char[]a, int index, int limit )	Returns the codePoint of the char array at the specified index where only the elements of the array with the index less than the specified limit being used.
codePointAt(CharSequence seq, int index)	Returns the codePoint at the specified index for the given CharSequence.
codePointBefore(char[]a, int index)	Returns the codePoint for the given array in the preceding index.
codePointBefore(char[]a, int index, int start)	Returns the codePoint for the given array in the preceding index where only the elements of the array with index greater than or equal to start are used.
codePointBefore(CharSequence, int index)	Returns the CodePoint for the given CharSequence int the preceding index.
codePointCount(char[]a, int offset, int count)	Returns the total number of Unicode codePoints in the given subarray of the char array argument.
codePointCount(CharSequence seq, int beginIndex, int endIndex)	Returns the number of Unicode codePoints provided in the given text range for the specified char sequence.
codePointOf(String name)	Returns the value of the codePoint for the given Unicode character specified by a particular character name.
compare(char x, char y)	Compares two character type values numerically.
compareTo(Character anotherCharacter)	Compares two Character type objects numerically.
digit(char ch, int radix)	Returns the numeric value for the given character in the specified index.
digit(int codePoint, int radix)	Returns the numeric value for the given character in the specified radix.
equals(object obj)	Compares the given object with the specified object.
forDigit(int digit, int radix)	Determines the presentation of the character for a particular digit in the given radix.
getDirectionality(char ch)	Returns the Unicode directionality property for the specified character.
getDirectionality(int codePoint)	Returns the Unicode directionality property for the specified codePoint.
getName(int codePoint)	Returns the Unicode name for the given codePoint or may return null if the codePoint is not assigned.
getNumericValue(char ch)	Returns the integer type value of the specified Unicode character.
getNumericValue(int codePoint)	Returns the integer type value of the specified Unicode codePoint.
getType(char ch)	Returns the value which indicates the general category of the character.
getType(int codePoint)	Returns the value which indicates the general category of the character.
hashcode()	Returns the hash code for the specified character. This method is equal to the result of invoking the charValue() method.
hashcode(char value)	Returns the hash code for a particular char value.
highSurrogate(int codePoint)	Returns the leading surrogate codePoint of a particular surrogate pair which represents the supplementary character in the UTF-16 encoding.
isAlphabetic(int codePoint)	Determines whether the given character is an alphabet or not.
isBmpCodePoint(int codePoint)	Determines whether the given character is in the Basic Multilingual Plane or not.
isDefined(char ch)	Determines whether the character is defined in the Unicode or not.
isDefined(int codePoint)	Determines whether the character(Unicode code point) is defined in the Unicode or not.
isDigit(char ch)	Determines whether the given character is a digit or not.
isDigit(int codePoint)	Determines whether the given character(Unicode code point) is a digit or not.
isHighSurrogate(char ch)	Determines whether the given char values is a Unicode high-surrogate code point or not.
isIndentifierIgnorable(char ch)	Determines whether the given character is considered to be an ignorable character in the Java identifier or not.
isIndentifierIgnorable(int codePoint)	Determines whether the given character(Unicode codePoint) is considered to be an ignorable character in the Java identifier or not.
isIdeographic(int codePoint)	Determines whether the specified character is a CJKV(Chinese, Japanese, Korean and Vietnamese) ideograph or not.
isISOControl(char ch)	Determines whether the given character is an ISO Control character or not.
isISOControl(int codePoint)	Determines whether the given character(Unicode code point) is an ISO Control character or not.
isJavaIdentifierPart(char ch)	Determines whether the given character is a part of the Java identifier other than the first character or not.
isJavaIdentifierPart(int codePoint)	Determines whether the given character(Unicode code point) is a part of the Java identifier other than the first character or not.
isJavaIdentifierStart(char ch)	Determines whether the given character is permissible as the first character in the Java identifier or not.
isJavaIdentifierStart(int codePoint)	Determines whether the given character(Unicode code point is permissible as the first character in the Java identifier or not.
isJavaLetter(char ch)	Replaced by the isJavaIdentifierStart(char).
isJavaLetterOrDigit(int codePoint)	Replaced by the isJavaIdentifierPart(char).
isLetter(char ch)	Determines whether the specified character is a letter or not.
isLetter(int codePoint)	Determines whether the specified character(Unicode code point) is a letter or not.
isLetterOrDigit(char ch)	Determines whether the specified character is a letter or digit or not.
isLetterOrDigit(int codePoint)	Determines whether the specified character(Unicode code point) is a letter or digit or not.
isLowerCase(char ch)	Determines whether the specified character is a lowercase character or not.
isLowerCase(int codePoint)	Determines whether the specifed character(Unicode code point) is a lowercase character or not.
isLowSurrogate(char ch)	Determines whether the given char value is a Unicode low-surrogate code unit or not.
isMirrored(char ch)	Determines whether the character is mirrored or not.
isMirrored(int codePoint)	Determines whether the character(Unicode code point) is mirrored or not.
isSpace(char ch)	Replaced by isWhiteSpace(char ch) method.
isSpaceChar(char ch)	Determines whether the specified character is a Unicode space character or not.
isSupplementaryCodePoint(int codePoint)	Determines whether the given character(Unicode code point) is in the range of supplementary characters or not.
isSurrogate(char ch)	Determines whether the given char value is a Unicode surrogate code unit.
isSurrogatePair(char high, char low)	Determines whether the given pair of char value is a valid Unicode surrogate pair or not.
isTitleCase(char ch)	Determines whether the given character is a titlecase character or not.
isTitleCase(int codePoint)	Determines whether the given character(Unicode code point) is a titlecase character or not.
isUnicodeIdentifierPart(char ch)	Determines whether the given character is a part of Unicode identifier or not.
isUnicodeIdentifierPart(int codePoint)	Determines whether the given character(unicofde code point) is a part of Unicode identifier or not.
isUnicodeIdentifierStart(char ch)	Determines whether the given character is permissible as the first character in the Unicode identifier or not.
isUnicodeIdentifierStart(int codePoint)	Determines whether the given character(Unicode code point) is permissible as the first character in the Unicode identifier or not.
isUpperCase(char ch)	Determines whether the given character is an uppercase character or not.
isUpperCase(int codePoint)	Determines whether the given character(Unicode code point) is an uppercase character or not.
isValidCodePoint(int codePoint)	Determines whether the given character is a valid Unicode code point value or not.
isWhitespace(char ch)	Determines whether the given character is a white space or not.
isWhitespace(int codePoint)	Determines whether the given character(Unicode code point)is a white space or not .
lowSurrogate(int codePoint)	Returns the low surrogate code unit(i.e trailing surrogate)of the surrogate pair which represents the supplementary character in the UTF-16 encoding.
offsetByCodePoints(char[]a, int start, int count, int index, int codePointOffset)	Returns the index for the given char subarray which is the offset from the given index by the codePointOffset code points.
offsetByCodePoints(CharSequence seq, int index, int codePointOffset)	Returns the index for the given char subarray which is the offset from the given index by the codePointOffset code points.
reverseBytes(char ch)	Returns the value obtained by reversing the order of the given bytes in the specified char values.
toChars(int codePoint)	Converts the specified character(Unicode code point) into its UTF-16 representation which is stored in a char array.
toChars(int codePoint, char[] dst, int dstIndex)	Converts the specified character(Unicode code point) into its UTF-16 representation.
toCodePoint(char high, char low)	Converts the given surrogate pair to its corresponding supplementary code point value.
toLowerCase(char ch)	Converts the character type argument to lowercase using case mapping information obtained from the Unicode Data file.
toLowerCase(int codePoint)	Converts the character type argument(Unicode code point) to lowercase using case mapping information obtained from the Unicode Data file.
toString()	Returns a String type object which represents the value of the character.
toString(char ch)	Returns a String type object which represents the specified character
toTitleCase(char ch)	Converts the character type argument to titlecase using case mapping information obtained from the Unicode Data file.
toTitleCase(int codePoint)	Converts the character type argument(Unicode code point) to lowercase using case mapping information obtained from the Unicode Data file.
toUpperCase(char ch)	Converts the character type argument to uppercase using case mapping information obtained from the Unicode Data file.
toUpperCase(int codePoint)	Converts the character type argument(Unicode code point) to uppercase using case mapping information obtained from the Unicode Data file.
valueOf(char c)	Returns the instance of a Character which represents the specified character value.

Example 1

import java.util.Scanner;
public class JavaCharacterExample1 {
   public static void main(String[] args) {
    // Ask the user for the first input. 
       System.out.print("Enter the first input:");
    // Use the Scanner class to get the user input.
       Scanner scanner = new Scanner(System.in);
    // Gets the user input.
       char[] value1 = scanner.nextLine().toCharArray();
       int result1 = 0;
    // Count the characters for a specific character.
       for (char ch1 : value1) {
       result1 = Character.charCount(ch1);
       }
    // Print the result.
        System.out.print("The value comes to: "+result1+"\n");
       
       System.out.print("Enter the second input:");
       char[] value2 = scanner.nextLine().toCharArray();
        for (char ch2 : value2) {
        int result2 = Character.hashCode(ch2);
       System.out.print("The hash code for the character '"+ch2+"' is given as:"+result2+"\n");
       }
      System.out.print("Enter the third input:");
       char[] value3 = scanner.nextLine().toCharArray();
       for (char ch3 : value3) {
      boolean result3 = Character.isDigit(ch3);
      if(result3){
System.out.println("The character '" + ch3 + "' is a digit. ");				
                }
      else{
System.out.println("The character '" + ch3 + "' is not a digit.");
           }	
      System.out.print("Enter the fourth input:");
       char[] value4 = scanner.nextLine().toCharArray();
       for (char ch4 : value4) {
      boolean result4 = Character.isISOControl(ch4);
      System.out.println("The fourth character '"+ch4+"' is an ISO Control:"+result4);              
         }
       }
   }
}

Output:

Enter the first input:89
The value comes to: 1
Enter the second input:J
The hash code for the character 'J' is given as:74
Enter the third input:5
The character '5' is a digit. 
Enter the fourth input:h
The fourth character 'h' is an ISO Control:false

Example 2

public class JavaCharacterExample2{
 public static void main(String[] args) {
      // Create four char primitives ch1, ch2, ch3 and ch4.
         char ch1, ch2, ch3, ch4;
      // Assign the values to ch1, ch2, ch3 and ch4.
         ch1 = 'T';
         ch2 = 'k';
         ch3 = '\n';
         ch4 = 'G';
      // Create four boolean primitives b1, b2, b3 and b4.
      boolean b1, b2, b3,b4;
      // Assign the results to b1, b2, b3 and b4.
      b1 = Character.isLetter(ch1);
      b2 = Character.isLowerCase(ch2);
      b3 = Character.isSpace(ch3);
      b4 = Character.isDefined(ch3);
      String str1 = " The first character is a letter: " + b1;
      String str2 = " The second character is a lower-case: " + b2;
      String str3 = " The third character is for space: " + b3;
      String str4 = " The fourth character is defined in Java identifier: " + b3;
      // Print the values of b1, b2, b3 and b4.
      System.out.println( str1 );
      System.out.println( str2 );
      System.out.println( str3 );
      System.out.println( str3 );
   }
}

Output:

The first character is a letter: true
 The second character is a lower-case: true
 The third character has a space: true
 The third character has a space: true

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