Question

如果我有以下数组：

    Dim Array(4, 10) As String
    Array(0, 0) = "100"
    Array(0, 1) = "200"
    Array(1, 0) = "300"
    Array(1, 1) = "400"
    Array(1, 2) = "500"
    Array(1, 3) = "600"

如何获得以下计数：

0 = 2
1 = 4

Answer 1

听起来您正在尝试计算数组每个维度中non-Nothing个值的数量。以下功能将允许您执行此操作

Public Function CountNonNothing(ByVal data As String(,), ByVal index As Integer) As Integer
    Dim count = 0
    For j = 0 To data.GetLength(1) - 1
        If data(index, j) IsNot Nothing Then
            count += 1
        End If
    Next
    Return count
End Function

它可以像这样调用

Dim count1 = CountNonNothing(Array, 0)
Dim count2 = CountNonNothing(Array, 1)

Answer 2

注意：我使用了C＃到VB转换器，所以希望VB语法正确。

我制作了一个简单的扩展方法，使这很简单：

Public NotInheritable Class Extensions
Private Sub New()
End Sub
<System.Runtime.CompilerServices.Extension> _
Public Shared Function GetNonNullItems(Of T)(array As T(,), index As Integer) As IEnumerable(Of T)
    For i As Integer = 0 To array.GetLength(index) - 1
        If array(index, i) IsNot Nothing Then
            yield Return array(index, i)
        End If
    Next
End Function
End Class

然后使用它：

Dim Array As String(,) = New String(4, 10) {}
Array(0, 0) = "100"
Array(0, 1) = "200"
Array(1, 0) = "300"
Array(1, 1) = "400"
Array(1, 2) = "500"
Array(1, 3) = "600"

Dim countArray0 As Integer = Array.GetNonNullItems(0).Count()
Dim countArray1 As Integer = Array.GetNonNullItems(1).Count()

扩展方法将返回为给定索引找到的所有非空项。通过它，您可以获得计数，过滤，查询或使用它们。

Answer 3

从c＃转换，但它可能是这样的。

Dim count As Integer() = New Integer(Array.GetLength(0) - 1) {}
For i As Integer = 0 To Array.GetLength(0) - 1
    For j As Integer = 0 To Array.GetLength(1) - 1
        If Array(i, j) IsNot Nothing Then
            count(i) += 1
        End If
    Next
Next

现在0's的数量将在count(0)，1's的数量将在count(1)，依此类推......

计算多维数组中的项目

3 个答案: