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We have worked with characters (char) as primitive data types. Now, we are ready to examine the Character class which offers a number of useful methods for manipulating characters.

Character is located in the java.lang package.
The full class name is java.lang.Character.
Remember, NO importing is needed to utilize the java.lang package.

Sample ways to engage these new methods:

System.out.println(Character.isDigit(value)); //prints the result char c = Character.toLowerCase('Q'); //c becomes 'q'

NOTE: All of these methods take a char as a parameter.

• You cannot pass an entire string to character methods. If you want to test the elements of a string, you must pass the string one element at a time.
• If you pass an integer to these methods, the methods will act upon the corresponding ASCII character associated with your integer (i.e. int i = 65; and char j = 'A'; are the same since in ASICC the letter A is assigned to 65). Read about ASCII below the table.

Method	Purpose
Character.isLetter()	determines whether a char value is a letter and returns "true" if the char is an upper or lower case letter.
Character.isDigit()	determines whether a char value is a digit and returns "true" if the char is 0 through 9.
Character.isLetterOrDigit()	determines whether a char value is a letter or a digit and returns "true" if that is the case.
Character.isascii()	returns "true" if the integer argument is in the ASCII range 0-127. Treats 128-255 as non-ASCII
Character.isWhitespace()	determines whether a char value is white space (such as a space, tab, or newline) and returns "true" if this is the case.
Character.isLowerCase()	determines whether a char value is lowercase and returns "true" if this is the case.
Character.isUpperCase()	determines whether a char value is uppercase and returns "true" if this is the case.
Character.toLowerCase()	returns the lowercase form of a char value c = Character.toLowerCase('Q'); //c becomes 'q'
Character.toUpperCase()	returns the uppercase form of a char value c = Character.toUpperCase('q'); //c becomes 'Q'
Character.toString()	returns a one-character String to represent the char value
Character.getNumericValue()	returns the int value associated with the character.

Java works with the American Standard Code for Information Interchange (ASCII) character set. The Character class includes character classification methods. A character is passed to the functions and the functions return values that can be stored or printed.

Basic ASCII Printable Characters: