# shmibs's solution

## to Leap in the Vim script Track

Published at Dec 01 2018 · 0 comments
Instructions
Test suite
Solution

#### Note:

This exercise has changed since this solution was written.

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.

## 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.

``````Execute (2000 is a leap year):
AssertEqual 1, IsLeap(2000)

Execute (2015 is not a leap year):
AssertEqual 0, IsLeap(2015)

Execute (2016 is a leap year):
AssertEqual 1, IsLeap(2016)

Execute (2100 is not a leap year):
AssertEqual 0, IsLeap(2100)``````
``````"
" This function takes a year and returns 1 if it's a leap year
" and 0 otherwise.
"
fun! IsLeap(number) abort
return a:number % 4 ? 0 : (a:number % 100 != 0) || (a:number % 400 == 0)
endfun``````