Exercism v3 launches on Sept 1st 2021. Learn more! 🚀🚀🚀
Sign up Log in
Avatar of neiesc

neiesc's solution

to Leap in the C# Track

Published at Mar 24 2019 · 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.

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.

Notes

The DateTime class in C# provides a built-in IsLeapYear method which you should pretend doesn't exist for the purposes of implementing this exercise.

Running the tests

To run the tests, run the command dotnet test from within the exercise directory.

Initially, only the first test will be enabled. This is to encourage you to solve the exercise one step at a time. Once you get the first test passing, remove the Skip property from the next test and work on getting that test passing. Once none of the tests are skipped and they are all passing, you can submit your solution using exercism submit Leap.cs

Further information

For more detailed information about the C# track, including how to get help if you're having trouble, please visit the exercism.io C# language page.

Source

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

LeapTest.cs

// This file was auto-generated based on version 1.5.1 of the canonical data.

using Xunit;

public class LeapTest
{
    [Fact]
    public void Year_not_divisible_by_4_in_common_year()
    {
        Assert.False(Leap.IsLeapYear(2015));
    }

    [Fact(Skip = "Remove to run test")]
    public void Year_divisible_by_2_not_divisible_by_4_in_common_year()
    {
        Assert.False(Leap.IsLeapYear(1970));
    }

    [Fact(Skip = "Remove to run test")]
    public void Year_divisible_by_4_not_divisible_by_100_in_leap_year()
    {
        Assert.True(Leap.IsLeapYear(1996));
    }

    [Fact(Skip = "Remove to run test")]
    public void Year_divisible_by_100_not_divisible_by_400_in_common_year()
    {
        Assert.False(Leap.IsLeapYear(2100));
    }

    [Fact(Skip = "Remove to run test")]
    public void Year_divisible_by_400_in_leap_year()
    {
        Assert.True(Leap.IsLeapYear(2000));
    }

    [Fact(Skip = "Remove to run test")]
    public void Year_divisible_by_200_not_divisible_by_400_in_common_year()
    {
        Assert.False(Leap.IsLeapYear(1800));
    }
}
using System;

public static class Leap
{
    public static bool IsLeapYear(int year)
    {
        var isDivisibleBy4 = year % 4 == 0;
        var isDivisibleBy100 = year % 100 == 0;
        var isDivisibleBy400 = year % 400 == 0;

        return isDivisibleBy4 && (!isDivisibleBy100 || isDivisibleBy400);
    }
}

Community comments

Find this solution interesting? Ask the author a question to learn more.

What can you learn from this solution?

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.

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