Character class

 

  The Character class lives in java.lang.  All its methods are static final.

 

  Several useful methods return a boolean:  isLetter(char),  isDigit(char), and  isJavaIdentifierStart(char)  (meaning  is it a letter, $ , or _ )

 

  Also isLetterOrDigit(char),  isLowerCase(char), and  isSpaceChar(char)

 

  These return a char:  toLowerCase(char), and  toUpperCase(char)