数组存储相同类型元素的固定大小顺序集合.数组用于存储数据集合，但将数组视为相同类型的变量集合通常更有用.
所有数组都包含连续的内存位置.最低地址对应第一个元素，最高地址对应最后一个元素.
要在VB.Net中声明数组，请使用Dim语句.例如，
Dim intData(30) ' an array of 31 elements Dim strData(20) As String ' an array of 21 strings Dim twoDarray(10, 20) As Integer 'a two dimensional array of integers Dim ranges(10, 100) 'a two dimensional array
您还可以在声明数组时初始化数组元素.例如，
Dim intData() As Integer = {12, 16, 20, 24, 28, 32}
Dim names() As String = {"Karthik", "Sandhya", _
"Shivangi", "Ashwitha", "Somnath"}
Dim miscData() As Object = {"Hello World", 12d, 16ui, "A"c}可以使用数组的索引存储和访问数组中的元素.以下程序演示了这个 :
Module arrayApl
Sub Main()
Dim n(10) As Integer ' n is an array of 11 integers '
Dim i, j As Integer
' initialize elements of array n '
For i = 0 To 10
n(i) = i + 100 ' set element at location i to i + 100
Next i
' output each array element's value '
For j = 0 To 10
Console.WriteLine("Element({0}) = {1}", j, n(j))
Next j
Console.ReadKey()
End Sub
End Module编译并执行上述代码时，会产生以下结果 :
Element(0) = 100 Element(1) = 101 Element(2) = 102 Element(3) = 103 Element(4) = 104 Element(5) = 105 Element(6) = 106 Element(7) = 107 Element(8) = 108 Element(9) = 109 Element(10) = 110
动态数组是可以根据程序需要确定尺寸和重新标注尺寸的数组.您可以使用 ReDim 语句声明动态数组.
ReDim语句的语法 :
ReDim [Preserve] arrayname(subscripts)
其中，
当您调整大小时，保留关键字有助于保留现有数组中的数据.
arrayname 是要重新标注的数组的名称.
下标指定新维度.
Module arrayApl Sub Main() Dim marks() As Integer ReDim marks(2) marks(0) = 85 marks(1) = 75 marks(2) = 90 ReDim Preserve marks(10) marks(3) = 80 marks(4) = 76 marks(5) = 92 marks(6) = 99 marks(7) = 79 marks(8) = 75 For i = 0 To 10 Console.WriteLine(i & vbTab & marks(i)) Next i Console.ReadKey() End Sub End Module
当编译并执行上述代码时，它会产生以下结果 :
0 85 1 75 2 90 3 80 4 76 5 92 6 99 7 79 8 75 9 0 10 0
VB.Net允许多维数组.多维数组也称为矩形数组.
您可以将字符串的二维数组声明为 :
Dim twoDStringArray(10, 20) As String
或者，一个三维整数变量数组 :
Dim threeDIntArray(10, 10, 10) As Integer
以下程序演示如何创建和使用二维数组 :
Module arrayApl
Sub Main()
' an array with 5 rows and 2 columns
Dim a(,) As Integer = {{0, 0}, {1, 2}, {2, 4}, {3, 6}, {4, 8}}
Dim i, j As Integer
' output each array element's value '
For i = 0 To 4
For j = 0 To 1
Console.WriteLine("a[{0},{1}] = {2}", i, j, a(i, j))
Next j
Next i
Console.ReadKey()
End Sub
End Module编译并执行上述代码时，会产生以下结果 :
a[0,0]: 0 a[0,1]: 0 a[1,0]: 1 a[1,1]: 2 a[2,0]: 2 a[2,1]: 4 a[3,0]: 3 a[3,1]: 6 a[4,0]: 4 a[4,1]: 8
Jagged数组是一个数组数组.下面的代码显示了一个名为得分的整数和负号的锯齿状数组;
Dim scores As Integer()() = New Integer(5)(){}以下示例说明使用锯齿状数组 :
Module arrayApl
Sub Main()
'a jagged array of 5 array of integers
Dim a As Integer()() = New Integer(4)() {}
a(0) = New Integer() {0, 0}
a(1) = New Integer() {1, 2}
a(2) = New Integer() {2, 4}
a(3) = New Integer() {3, 6}
a(4) = New Integer() {4, 8}
Dim i, j As Integer
' output each array element's value
For i = 0 To 4
For j = 0 To 1
Console.WriteLine("a[{0},{1}] = {2}", i, j, a(i)(j))
Next j
Next i
Console.ReadKey()
End Sub
End Module当编译并执行上述代码时，它会产生以下结果 :
a[0][0]: 0 a[0][1]: 0 a[1][0]: 1 a[1][1]: 2 a[2][0]: 2 a[2][1]: 4 a[3][0]: 3 a[3][1]: 6 a[4][0]: 4 a[4][1]: 8
Array类是VB.Net中所有数组的基类.它在System命名空间中定义. Array类提供了各种属性和方法来处理数组.
下表提供了一些最常用的属性和方法数组类的属性 :
| Sr.No | Property Name&描述 |
|---|---|
| 1 | IsFixedSize 获取一个值，该值指示数组是否具有固定大小. |
| 2 | IsReadOnly 获取一个值，该值指示数组是否为只读. |
| 3 | Length 获取32位整数，表示数组所有维度中元素的总数. |
| 4 | LongLength 获取64-位整数，表示数组所有维度中元素的总数. |
| 5 | Rank 获取等级(数量)数组的维度. |
下表提供了数组类中最常用的方法 :
| Sr.No | 方法名称&描述 |
|---|---|
| 1 | Public Shared Sub Clear (array As Array, index As Integer, length As Integer) 将数组中的元素范围设置为零，为false，或者为null，具体取决于元素类型. |
| 2 | Public Shared Sub Copy (sourceArray As Array, destinationArray As Array, length As Integer) 从第一个元素开始复制Array中的一系列元素，并从第一个元素开始将它们粘贴到另一个Array中.长度指定为32位整数. |
| 3 | Public Sub CopyTo (array As Array, index As Integer) 副本当前一维Array的所有元素到指定的一维Array从指定的目标Array索引开始.索引被指定为32位整数. |
| 4 | Public Function GetLength (dimension As Integer) As Integer 获取32 -bit integer，表示Array指定维度中的元素数. |
| 5 | Public Function GetLongLength (dimension As Integer) As Long 获取一个64位整数，表示数组指定维度中的元素数. |
| 6 | Public Function GetLowerBound (dimension As Integer) As Integer 获取数组中指定维度的下限. |
| 7 | Public Function GetType As Type 获取当前实例的Type(继承自Object). |
| 8 | Public Function GetUpperBound (dimension As Integer) As Integer 获取数组中指定维度的上限. |
| 9 | Public Function GetValue (index As Integer) As Object 获取一维数组中指定位置的值.索引被指定为32位整数. |
| 10 | Public Shared Function IndexOf (array As Array,value As Object) As Integer 搜索指定的对象并返回整个一维数组中第一个匹配项的索引. |
| 11 | Public Shared Sub Reverse (array As Array) 反转整个一维数组中元素的顺序. |
| 12 | Public Sub SetValue (value As Object, index As Integer) 为一维数组中指定位置的元素设置一个值.索引被指定为32位整数. |
| 13 | Public Shared Sub Sort (array As Array) 对元素进行排序使用数组中每个元素的IComparable实现的整个一维数组. |
| 14 | Public Overridable Function ToString As String 返回表示当前对象的字符串(继承自Object). |
完整有关Array类属性和方法的列表，请参阅Microsoft文档.
以下程序演示了如何使用Array类的一些方法:
Module arrayApl
Sub Main()
Dim list As Integer() = {34, 72, 13, 44, 25, 30, 10}
Dim temp As Integer() = list
Dim i As Integer
Console.Write("Original Array: ")
For Each i In list
Console.Write("{0} ", i)
Next i
Console.WriteLine()
' reverse the array
Array.Reverse(temp)
Console.Write("Reversed Array: ")
For Each i In temp
Console.Write("{0} ", i)
Next i
Console.WriteLine()
'sort the array
Array.Sort(list)
Console.Write("Sorted Array: ")
For Each i In list
Console.Write("{0} ", i)
Next i
Console.WriteLine()
Console.ReadKey()
End Sub
End Module编译并执行上述代码时，会产生以下结果 :
Original Array: 34 72 13 44 25 30 10 Reversed Array: 10 30 25 44 13 72 34 Sorted Array: 10 13 25 30 34 44 72
