Indicates if a wide character is classed either as alphabetic or
    as a digit in the program's current locale.

    Format

      #include  <wctype.h> (ISO C)

      #include  <wchar.h> (XPG4)

      int iswalnum  (wint_t wc);

1 - Argument

 wc

    An object of type wint_t. The value of character must be
    representable as a wchar_t in the current locale, or must equal
    the value of the macro WEOF. If it has any other value, the
    behavior is undefined.

2 - Return Values

    nonzero            If alphanumeric.
    0                  If not alphanumeric.