Given a year, report if it is a leap year.
The tricky thing here is that a leap year in the Gregorian calendar occurs:
on every year that is evenly divisible by 4 except every year that is evenly divisible by 100 unless the year is also evenly divisible by 400
For example, 1997 is not a leap year, but 1996 is. 1900 is not a leap year, but 2000 is.
If your language provides a method in the standard library that does this look-up, pretend it doesn't exist and implement it yourself.
Though our exercise adopts some very simple rules, there is more to learn!
For a delightful, four minute explanation of the whole leap year phenomenon, go watch this youtube video.
Go through the setup instructions for PL/SQL to get ready to code:
Execute the tests by calling the
run method in the respective
The necessary code should be contained at the end of the test package.
As an example, the test for the hamming exercise would be run using
begin ut_hamming#.run; end; /
JavaRanch Cattle Drive, exercise 3 http://www.javaranch.com/leap.jsp
It's possible to submit an incomplete solution so you can see how others have completed the exercise.
create or replace package ut_year# is procedure run; end ut_year#; / create or replace package body ut_year# is procedure test ( i_descn varchar2 ,i_exp varchar2 ,i_act varchar2 ) is begin if i_exp = i_act then dbms_output.put_line('SUCCESS: ' || i_descn); else dbms_output.put_line('FAILURE: ' || i_descn || ' - expected ' || nvl(i_exp, 'null') || ', but received ' || nvl(i_act, 'null')); end if; end test; procedure run is begin test(i_descn => 'test_leap_year' , i_exp => 'Yes, 1996 is a leap year' , i_act => year#.is_leap(1996)); test(i_descn => 'test_non_leap_year' , i_exp => 'No, 1997 is not a leap year', i_act => year#.is_leap(1997)); test(i_descn => 'test_non_leap_even_year', i_exp => 'No, 1998 is not a leap year', i_act => year#.is_leap(1998)); test(i_descn => 'test_century' , i_exp => 'No, 1900 is not a leap year', i_act => year#.is_leap(1900)); test(i_descn => 'test_fourth_century' , i_exp => 'Yes, 2400 is a leap year' , i_act => year#.is_leap(2400)); end run; end ut_year#; / begin ut_year#.run; end; /
create or replace package year# is function is_leap (in_year pls_integer) return varchar2; end year#; / create or replace package body year# is function is_leap (in_year pls_integer) return varchar2 is is_leap boolean; begin is_leap := case when mod(in_year, 100) = 0 then mod(in_year, 400) = 0 else mod(in_year, 4) = 0 end; return case is_leap when true then 'Yes, ' || in_year || ' is a leap year' else 'No, ' || in_year || ' is not a leap year' end; end; end year#; /
A huge amount can be learned from reading other people’s code. This is why we wanted to give exercism users the option of making their solutions public.
Here are some questions to help you reflect on this solution and learn the most from it.