新加入的数组缺少一个元素 - vb

Question

我正在尝试合并我的 2 个数组，
Dim arr1(3) As String
arr1(0) = "a"
arr1(1) = "b"
arr1(2) = "c"
arr1(3) = "d"

Dim arr2(4) As String
arr2(0) = "a"
arr2(1) = "x"
arr2(2) = "x"
arr2(3) = "b"
arr2(4) = "z"

Dim arr3 As String()
ReDim arr3(UBound(arr1) + UBound(arr2) + 1)

    Dim i As Integer
    For i = 0 To UBound(arr1)
        arr3(i * 2) = arr1(i)
        arr3(i * 2 + 1) = arr2(i)
        Label8.Text = String.Join(",", arr3)

合并后发生的事情是仅打印它的单个值

Dim r = From s In arr3
Group By s Into Group, Count()
Where Count = 1 Select s
Order By s
Label9.Text = String.Join(",", r)
Next i

购买它只打印 ,c,d，它应该在合并它们后打印在两个数组中出现一次的所有单个元素，应该是 c,d,z。我的代码有什么问题？谢谢。

Answer 1

由于两个源数组可以有不同的上限，您将不得不使用两者中的较高者进行迭代，并确保不要访问较短数组范围之外的索引

Dim arr1() As String = {"a", "b", "c", "d"}
Dim arr2() As String = {"a", "x", "x", "b", "z"}

Dim arr3(arr1.Length + arr2.Length - 1) As String

Dim iDestination As Integer = 0
For i As Integer = 0 To Math.Max(UBound(arr1), UBound(arr2))
    If i <= UBound(arr1) Then
        arr3(iDestination) = arr1(i)
        iDestination += 1
    End If
    If i <= UBound(arr2) Then
        arr3(iDestination) = arr2(i)
        iDestination += 1
    End If
Next

这会像您一样交错结果。

如果不需要交错并且您只是对结果感兴趣（而不是算法），您可以简单地执行：

Dim arr1() As String = {"a", "b", "c", "d"}
Dim arr2() As String = {"a", "x", "x", "b", "z"}

Dim r = From s In arr1.Concat(arr2)
    Group By s Into Group, Count()
    Where Count = 1 Select s
    Order By s

这 returns 元素在 arr1 或 arr2 中恰好出现一次。

Answer 2

另一种方法使用Array.CopyTo

Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
    Dim arr1(3) As String
    arr1(0) = "a"
    arr1(1) = "b"
    arr1(2) = "c"
    arr1(3) = "d"

    Dim arr2(4) As String
    arr2(0) = "a"
    arr2(1) = "x"
    arr2(2) = "x"
    arr2(3) = "b"
    arr2(4) = "z"

    Dim arr3 As String()
    ReDim arr3(arr1.Length + arr2.Length)

    arr1.CopyTo(arr3, 0)
    arr2.CopyTo(arr3, arr1.Length)

    For Each s As String In arr3
        Debug.Print(s)
    Next
End Sub

新加入的数组缺少一个元素 - vb

newly joined array is missing an element - vb

vb.net

array-merge