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Published at Aug 18 2020
·
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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.

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.

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

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

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.

```
"
" 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
return (a:year % 400 == 0 || a:year % 100 != 0 && a:year % 4 == 0)
endfunction
```

A huge amount can be learned from reading other peopleâ€™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.

- What compromises have been made?
- Are there new concepts here that you could read more about to improve your understanding?

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