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to Leap in the Vim script Track

Published at Sep 09 2020 · 0 comments
Instructions
Test suite
Solution

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.

Notes

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.

How to run the tests

If you don't know how to run Vader tests, see: Tests.

For general information about the Vim script track, see: Help.

Source

JavaRanch Cattle Drive, exercise 3 http://www.javaranch.com/leap.jsp

Submitting Incomplete Solutions

It's possible to submit an incomplete solution so you can see how others have completed the exercise.

leap.vader

"
" Version: 1.4.0
"

Execute (year not divisible by 4: common year):
  let year = 2015
  let expected = 0
  AssertEqual expected, LeapYear(year)

Execute (year divisible by 4, not divisible by 100: leap year):
  let year = 1996
  let expected = 1
  AssertEqual expected, LeapYear(year)

Execute (year divisible by 100, not divisible by 400: common year):
  let year = 2100
  let expected = 0
  AssertEqual expected, LeapYear(year)

Execute (year divisible by 400: leap year):
  let year = 2000
  let expected = 1
  AssertEqual expected, LeapYear(year)

Execute (year divisible by 200, not divisible by 400: common year):
  let year = 1800
  let expected = 0
  AssertEqual expected, LeapYear(year)
"
" This function takes a year and returns 1 if it's a leap year
" and 0 otherwise.
"
function! LeapYear(year) abort
  let divisible_by_4 = a:year % 4 == 0
  let divisible_by_100 = a:year % 100 == 0
  let divisible_by_400 = a:year % 400 == 0

  if divisible_by_4 && !divisible_by_100 || divisible_by_400
    return 1
  endif

  return 0
endfunction

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