CODEWITHSUNDEEP
c#
AMeh
AMeh

Reputation: 211

Find next leap year from today's date in c#

I want to find the next leap year from today's date.

For ex.,

Date        NextLeapDate
-----       ------------
2016-01-01   2016-02-29
2016-05-24   2020-02-29
2017-02-03   2020-02-29

This is what I have so far to get the next leap year but it's getting me wrong value,

public int GetNextLeapYear(int year)
{
    bool isLeapYear = false;

    while (true)
    {
        if (DateTime.IsLeapYear(year))
        {
            isLeapYear = true;
        }
        else
        {
            year = year + 1;
            GetNextLeapYear(year);
        }
        break;
    }
    return year;
}

Upvotes: 1

Views: 1889

Answers (4)

Nate
Nate

Reputation: 847

To use recursion to find the next leap year, you can change your method like so.

public int GetNextLeapYear(int year)
{
    if (!DateTime.IsLeapYear(year))
    {
        return GetNextLeapYear(year + 1);
    }
    return year;
}

Using recursion, you don't need the While loop, you just need to check to see if you need to continue or return the value. This also allows you to get rid of variables that are not needed. @poke answer is more complete counting for the actual month that you are in and such. I only answered this way to keep with using recursion like you had done.

Upvotes: 1

Paul Stelian
Paul Stelian

Reputation: 1379

Your current code is only a part of the program? The below code is copied from the question and changed with my suggestion edit (as well as other simplifications) to make it work correctly.

public int GetNextLeapYear(int year)
{
    if (DateTime.IsLeapYear(year))
    {
        return year;
    }
    else
    {
        year = year + 1;
        return GetNextLeapYear(year);
    }
}

Upvotes: 2

poke
poke

Reputation: 387527

Something like this:

DateTime GetNextLeapDate (DateTime baseDate)
{
    int year = baseDate.Year;

    // start in the next year if we’re already in March
    if (baseDate.Month > 2)
        year++;

    // find next leap year
    while (!DateTime.IsLeapYear(year))
        year++;

    // get last of February
    return new DateTime(year, 2, 29);
}

Note that we need to skip checking the current year if (and only if) the base date is already ahead of March (i.e. a possible leap day is already over). That way, we don’t get a result of February 29th, 2016 for e.g. today (time of this post).

Used like this, it returns the desired dates:

Console.WriteLine(GetNextLeapDate(new DateTime(2016, 01, 01))); // 2016-02-29
Console.WriteLine(GetNextLeapDate(new DateTime(2016, 05, 24))); // 2020-02-29
Console.WriteLine(GetNextLeapDate(new DateTime(2017, 02, 03))); // 2020-02-29

Upvotes: 6

Waldir J. Pereira Junior
Waldir J. Pereira Junior

Reputation: 836

You don't need recursion. Try this:

public int GetNextLeapYear(int year)
{
    while (true)
    {
        if (DateTime.IsLeapYear(year))
        {
            return year;
        }
        year = year + 1;
    }
}

Upvotes: 2

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