Array.Length Proprietà

  • Riferimento

Definizione

Spazio dei nomi:
System
Assembly:
System.Runtime.dll
Assembly:
mscorlib.dll
Assembly:
netstandard.dll
Source:
Array.CoreCLR.cs
Source:
Array.CoreCLR.cs
Source:
Array.CoreCLR.cs

Ottiene il numero totale di elementi in tutte le dimensioni di Array.

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

Valore della proprietà

Int32

Numero totale di elementi in tutte le dimensioni di Array; zero se nella matrice non sono presenti elementi.

Eccezioni

OverflowException

La matrice è multidimensionale e contiene più elementi Int32.MaxValue .

Esempio

Nell'esempio seguente viene utilizzata la Length proprietà per ottenere il numero totale di elementi in una matrice. Usa inoltre il GetUpperBound metodo per determinare il numero di elementi in ogni dimensione di una matrice multidimensionale.

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

open System


let showArrayInfo (arr: Array) =
    printfn $"Length of Array:      {arr.Length,3}"
    printfn $"Number of Dimensions: {arr.Rank,3}"
    // For multidimensional arrays, show number of elements in each dimension.
    if arr.Rank > 1 then
        for dimension = 1 to arr.Rank do
            printfn $"   Dimension {dimension}: {arr.GetUpperBound(dimension - 1) + 1,3}"
    printfn ""

// Declare a single-dimensional string array
let array1d = [| "zero"; "one"; "two"; "three" |]
showArrayInfo array1d

// Declare a two-dimensional string array
let array2d = 
    array2D [ [ "zero"; "0" ]; [ "one"; "1" ]
              [ "two"; "2" ]; [ "three"; "3" ]
              [ "four"; "4" ]; [ "five"; "5" ] ]

showArrayInfo array2d

// Declare a three-dimensional integer array
let array3d = Array3D.create 2 2 3 "zero"

showArrayInfo array3d

// 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

Commenti

Il recupero del valore di questa proprietà è un'operazione O(1).

Si applica a

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