Array.Length Array.Length Array.Length Array.Length Property

定義

Array のすべての次元内の要素の総数を取得します。Gets the total number of elements in all the dimensions of the Array.

public:
 property int Length { int get(); };
public int Length { get; }
member this.Length : int
Public ReadOnly Property Length As Integer

プロパティ値

Array のすべての次元内の要素の総数。配列内に要素がない場合はゼロ。The total number of elements in all the dimensions of the Array; zero if there are no elements in the array.

例外

配列は多次元配列で、MaxValue 以上の要素を含みます。The array is multidimensional and contains more than MaxValue elements.

次の例では、Length配列の要素の合計数を取得するプロパティ。The following example uses the Length property to get the total number of elements in an array. また、使用、GetUpperBound多次元配列の各次元内の要素の数を決定するメソッド。It also uses the GetUpperBound method to determine the number of elements in each dimension of a multidimensional array.

using System;

public class Example
{
    public static void Main()
    {
        // Declare a single-dimensional string array
        String[] array1d = { "zero", "one", "two", "three" };
        ShowArrayInfo(array1d);

        // Declare a two-dimensional string array
        String[,] array2d = { { "zero", "0" }, { "one", "1" }, 
                           { "two", "2" }, { "three", "3"},
                           { "four", "4" }, { "five", "5" } };
        ShowArrayInfo(array2d);

        // Declare a three-dimensional integer array  
        int[, ,] array3d = new int[,,] { { { 1, 2, 3 }, { 4, 5, 6 } }, 
                                       { { 7, 8, 9 }, { 10, 11, 12 } } };
        ShowArrayInfo(array3d);
    }

    private static void ShowArrayInfo(Array arr)
    {
        Console.WriteLine("Length of Array:      {0,3}", arr.Length);
        Console.WriteLine("Number of Dimensions: {0,3}", arr.Rank);
        // For multidimensional arrays, show number of elements in each dimension.
        if (arr.Rank > 1) {
            for (int dimension = 1; dimension <= arr.Rank; dimension++)
                Console.WriteLine("   Dimension {0}: {1,3}", dimension,
                                  arr.GetUpperBound(dimension - 1) + 1);
        }
        Console.WriteLine();
    }
}
// The example displays the following output:
//       Length of Array:        4
//       Number of Dimensions:   1
//       
//       Length of Array:       12
//       Number of Dimensions:   2
//          Dimension 1:   6
//          Dimension 2:   2
//       
//       Length of Array:       12
//       Number of Dimensions:   3
//          Dimension 1:   2
//          Dimension 2:   2
//          Dimension 3:   3
Module Example
    Public Sub Main()
        ' Declare a single-dimensional string array
        Dim array1d() As String = {"zero", "one", "two", "three"}
        ShowArrayInfo(array1d)

        ' Declare a two-dimensional string array
        Dim array2d(,) As String = {{"zero", "0"}, {"one", "1"},
                                     {"two", "2"}, {"three", "3"},
                                     {"four", "4"}, {"five", "5"}}
        ShowArrayInfo(array2d)

        ' Declare a three-dimensional integer array  
        Dim array3d(,,) As Integer = New Integer(,,) {{{1, 2, 3}, {4, 5, 6}},
                                        {{7, 8, 9}, {10, 11, 12}}}
        ShowArrayInfo(array3d)

    End Sub

    Private Sub ShowArrayInfo(arr As Array)
        Console.WriteLine("Length of Array:      {0,3}", arr.Length)
        Console.WriteLine("Number of Dimensions: {0,3}", arr.Rank)
        ' For multidimensional arrays, show number of elements in each dimension.
        If arr.Rank > 1 Then
            For dimension As Integer = 1 To arr.Rank
                Console.WriteLine("   Dimension {0}: {1,3}", dimension,
                                  arr.GetUpperBound(dimension - 1) + 1)
            Next
        End If
        Console.WriteLine()
    End Sub
End Module
' The example displays the following output:
'       Length of Array:        4
'       Number of Dimensions:   1
'       
'       Length of Array:       12
'       Number of Dimensions:   2
'          Dimension 1:   6
'          Dimension 2:   2
'       
'       Length of Array:       12
'       Number of Dimensions:   3
'          Dimension 1:   2
'          Dimension 2:   2
'          Dimension 3:   3

注釈

このプロパティ値を取得することは、O(1) 操作になります。Retrieving the value of this property is an O(1) operation.

適用対象

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