Summary of Classes and Interfaces - Absolute Java - page 1155

public static boolean isLowerCase( char argument)
Returns true if its argument is a lowercase letter; otherwise returns false.
EXAMPLES
Character.isLowerCase('a') returns true . Character.isLowerCase('A') and
Character.isLowerCase('%') both return false .
public static boolean isUpperCase( char argument)
Returns true if its argument is an uppercase letter; otherwise returns false.
EXAMPLES
Character.isUpperCase('A') returns true . Character.isUpperCase('a') and
Character.isUpperCase('%') both return false .
public static boolean isWhitespace( char argument)
Returns true if its argument is a whitespace character; otherwise returns false . Whitespace
characters are those that print as whitespace, such as the space character (blank character), the
tab character ( '\t' ), and the new-line character ( '\n' ).
EXAMPLES
Character.isWhitespace(' ') returns true . Character.isWhitespace('A') returns
false .
public static char toLowerCase( char argument)
Returns the lowercase version of its argument . If the argument is not a letter, it is returned
unchanged.
EXAMPLE
Character.toLowerCase('a') and Character.toLowerCase('A') both return 'a' .
public static char toUpperCase( char argument)
Returns the uppercase version of its argument . If the argument is not a letter, it is returned
unchanged.
EXAMPLE
Character.toUpperCase('a') and Character.toUpperCase('A') both return 'A' .