? :                      Condition operator (ternary)
 
 exp ? e1 : e2           Ternary conditional operator
 exp                     any scalar expression (int, char, enum)
 e1, e2                  any arithmetic structure, union, or pointer
                         expression
 
    The ? : operator evaluates either expression e1 or e2, depending upon
    the truth of e1.  If exp yields a non-zero value (TRUE), e1 is
    evaluated and that is the value returned; otherwise, e2 is evaluated,
    and that is the value returned.
 
           k = (i > j) ? i : j;   /* This is equivalent to:  k = max(i,j) */