1 declare
 2   judge      varchar2(200);
 3   year_input number;
 4 begin
 5   year_input := ‘&输入年份‘;
 6   if (mod(year_input, 400) = 0 or
 7      (mod(year_input, 4) = 0 and mod(year_input, 100) != 0)) then
 8     judge := ‘Leap Year‘;
 9   else
10     judge := ‘Not a Leap Year‘;
11     dbms_output.put_line(judge);
12   end if;
13 end;