# DateTime.IsLeapYear(Int32) メソッド

## 定義

``````public:
static bool IsLeapYear(int year);``````
``public static bool IsLeapYear (int year);``
``static member IsLeapYear : int -> bool``
``Public Shared Function IsLeapYear (year As Integer) As Boolean``

year
Int32

4 桁の年。

#### 戻り値

Boolean

`true` が閏年である場合は `year`。それ以外の場合は `false`

#### 例外

`year` が 1 未満であるか、または 9999 を超えています。

## 例

``````using System;

public class IsLeapYear
{
public static void Main()
{
for (int year = 1994; year <= 2014; year++)
{
if (DateTime.IsLeapYear(year))
{
Console.WriteLine("{0} is a leap year.", year);
DateTime leapDay = new DateTime(year, 2, 29);
Console.WriteLine("   One year from {0} is {1}.",
leapDay.ToString("d"),
nextYear.ToString("d"));
}
}
}
}
// The example produces the following output:
//       1996 is a leap year.
//          One year from 2/29/1996 is 2/28/1997.
//       2000 is a leap year.
//          One year from 2/29/2000 is 2/28/2001.
//       2004 is a leap year.
//          One year from 2/29/2004 is 2/28/2005.
//       2008 is a leap year.
//          One year from 2/29/2008 is 2/28/2009.
//       2012 is a leap year.
//          One year from 2/29/2012 is 2/28/2013.
``````
``````open System

[ 1994..2014 ]
|> List.filter DateTime.IsLeapYear
|> List.iter (fun year ->
printfn \$"{year} is a leap year."
let leapDay = DateTime(year, 2, 29)
printfn \$"   One year from {leapDay:d} is {nextYear:d}.")

// The example produces the following output:
//       1996 is a leap year.
//          One year from 2/29/1996 is 2/28/1997.
//       2000 is a leap year.
//          One year from 2/29/2000 is 2/28/2001.
//       2004 is a leap year.
//          One year from 2/29/2004 is 2/28/2005.
//       2008 is a leap year.
//          One year from 2/29/2008 is 2/28/2009.
//       2012 is a leap year.
//          One year from 2/29/2012 is 2/28/2013.
``````
``````Module IsLeapYear
Public Sub Main()
For year As Integer = 1994 to 2014
If DateTime.IsLeapYear(year) Then
Console.WriteLine("{0} is a leap year.", year)
Dim leapDay As New Date(year, 2, 29)
Dim nextYear As Date = leapDay.AddYears(1)
Console.WriteLine("   One year from {0} is {1}.", _
leapDay.ToString("d"), _
nextYear.ToString("d"))
End If
Next
End Sub
End Module
' The example displays the following output:
'       1996 is a leap year.
'          One year from 2/29/1996 is 2/28/1997.
'       2000 is a leap year.
'          One year from 2/29/2000 is 2/28/2001.
'       2004 is a leap year.
'          One year from 2/29/2004 is 2/28/2005.
'       2008 is a leap year.
'          One year from 2/29/2008 is 2/28/2009.
'       2012 is a leap year.
'          One year from 2/29/2012 is 2/28/2013.
``````

## 注釈

`year` は、4 桁の底 10 の数値として指定されます。たとえば、1996 などです。

`year` は常にグレゴリオ暦の年として解釈されます。 特定の年が他のカレンダーで閏年であったかどうかを判断するには、そのカレンダー オブジェクトの `IsLeapYear` メソッドを呼び出します。