Indicates if a character is classed as an uppercase character in
    the program's current locale.

    Format

      #include  <ctype.h>

      int isupper  (int character);

1 - Argument

 character

    An object of type int. The value of character must be
    representable as an unsigned char or must equal the value of the
    macro EOF. If it has any other value, the behavior is undefined.

2 - Return Values

    nonzero            If an uppercase alphabetic character.
    0                  If not an uppercase alphabetic character.