DateTime.IsLeapYear(Int32) メソッド

  • リファレンス

定義

名前空間:
System
アセンブリ:
System.Runtime.dll
アセンブリ:
mscorlib.dll
アセンブリ:
netstandard.dll
ソース:
DateTime.cs
ソース:
DateTime.cs
ソース:
DateTime.cs

指定された年が閏年かどうかを示す値を返します。

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

パラメーター

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

ArgumentOutOfRangeException

year が 1 未満であるか、または 9999 を超えています。

例

次の例では、 メソッドを IsLeapYear 使用して、1994 年から 2014 年までの年が閏年かどうかを判断します。 この例では、 メソッドを使用して閏日に年を追加する場合 AddYears の結果も示しています。

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);
            DateTime nextYear = leapDay.AddYears(1);
            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)
    let nextYear = leapDay.AddYears 1
    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 番号として指定されます。たとえば、1996 年です。

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の閏年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。

適用対象