Character Literals andthe cctype Library
isalpha(c) True if c is alphabetic
isupper(c) True if c is upper case
islower(c) True if c is lower case
isdigit(c) True if c is decimal digit char
isxdigit(c) True if c is hexidecimal digit
isalnum(c) True if c is alphabetic or numeric
isspace(c) True if c is whitespace (space, tab or newline)
isprint(c)} True if c is a printable character (8 bit only)