Question

给定某种值集合（数组或某种集合），如何生成一组不同的值？

Answer 1

使用Scripting.Dictionary（工具 - ＆gt; 引用... - ＆gt; Microsoft Scripting Runtime ）：

Function Unique(values As Variant) As Variant()
    'Put all the values as keys into a dictionary
    Dim dict As New Dictionary
    Dim val As Variant
    For Each val In values
        dict(val) = 1
    Next
    Unique = dict.Keys 'This cannot be done with a Collection, which doesn't expose its keys
End Function

在VBScript中，或者在VBA中，如果您更喜欢使用后期绑定（没有显式类型的变量）：

Function Unique(values)
    Dim dict, val
    Set dict = CreateObject("Scripting.Dictionary")
    For Each val In values
    ...

如果在Mac上运行VBA（没有Microsoft Scripting Runtime），则可以使用drop-in replacement for Dictionary。

一些例子：

另一个选项（仅限VBA）是使用Collection。它有点尴尬，因为在没有抛出错误的情况下无法设置现有密钥，并且因为必须手动创建返回的数组：

Function Unique(values As Variant) As Variant()
    Dim col As New Collection, val As Variant, i As Integer
    For Each val In values
        TryAdd col, val, val
    Next
    Dim ret() As Variant
    Redim ret(col.Count - 1)
    For i = 0 To col.Count-1
        ret(i) = col(i+1)
    Next
    Unique = ret
End Function

Sub TryAdd(col As Collection, item As Variant, key As String)
    On Error Resume Next
    col.Add(item, key)
End Sub

如何获得一组独特的值？

1 个答案: