Array.Length 属性
定义
重要
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获取 Array 的所有维度中的元素总数。
public:
property int Length { int get(); };public int Length { get; }member this.Length : intPublic ReadOnly Property Length As Integer属性值
Array 的所有维度中的元素总数；如果数组中无元素，则为零。
例外
数组是多维数组，包含的元素超过 Int32.MaxValue 。
示例
以下示例使用 Length 属性获取数组中的元素总数。 它还使用 GetUpperBound 方法确定多维数组的每个维度中的元素数。
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
注解
检索此属性的值的运算复杂度为 O(1)。
