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

定義

取得 Array 所有維度的元素總數。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

屬性值

Array 所有維度的項目總數;如果陣列中沒有項目,則為零。The total number of elements in all the dimensions of the Array; zero if there are no elements in the array.

例外狀況

陣列是多維度並包含超過 MaxValue 的項目數。The array is multidimensional and contains more than MaxValue elements.

範例

下列範例會使用Length屬性,以取得陣列中的項目總數。The following example uses the Length property to get the total number of elements in an array. 它也會使用GetUpperBound方法,以判斷每個維度的多維陣列中的項目數。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

備註

擷取這個屬性的值是一種 O(1) 運算。Retrieving the value of this property is an O(1) operation.

適用於

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