Question

我有一个对象数组，称为用于保存项目GUID列表及其数量的订单。

Dim orders As Object(,) = {{"ItemA", 11}, {"ItemB", 10}, {"ItemA", 2}, {"ItemB", 1}}

我想将其转换为以下内容：

Dim orders As Object(,) = {{"ItemA", 13}, {"ItemB", 11}}

换句话说，我希望有一个明确的项目选择，其中包含该项目的记录总数。我可以用LINQ做这个，还是应该只使用for循环？

Answer 1

您可以使用Dictionary(Of TKey, TValue)按GUID分组

Dim orders As Object(,) = {{"ItemA", 11}, {"ItemB", 10}, {"ItemA", 2}, {"ItemB", 1}}

Dim ordersSum As New Dictionary(Of String, Int32)()
For orderIndex As Int32 = 0 To orders.GetUpperBound(0)
    If ordersSum.ContainsKey(orders(orderIndex, 0)) = True Then
        ordersSum(orders(orderIndex, 0)) += orders(orderIndex, 1)
    Else
        ordersSum.Add(orders(orderIndex, 0), orders(orderIndex, 1))
    End If
Next

然后如果Dictionary类型不被允许，你真的需要一个多维数组作为返回类型

Dim result As Object(,) = New Object(ordersSum.Count - 1, 1) {}
Dim index As Int32 = 0
For Each key As String In ordersSum.Keys
    result(index, 0) = key
    result(index, 1) = ordersSum(key)
    index += 1
Next

结合Array的第二个元素

1 个答案: