使用ParamArray将参数的变量#传递给内置函数

Function CustomJoin(ParamArray args() As Variant) As String
    Dim result As String
    result = Join(args, ", ")
    CustomJoin = result
End Function

Sub TestCustomJoin()
    Dim str1 As String
    Dim str2 As String
    Dim str3 As String
    
    str1 = "apple"
    str2 = "banana"
    str3 = "cherry"
    
    Debug.Print CustomJoin(str1, str2, str3) ' 输出: apple, banana, cherry
    Debug.Print CustomJoin(str1, str2)       ' 输出: apple, banana
    Debug.Print CustomJoin(str1)            ' 输出: apple
End Sub

Function SafeJoin(ParamArray args() As Variant) As String
    Dim result As String
    Dim i As Integer
    Dim arg As Variant
    
    For i = LBound(args) To UBound(args)
        If Not IsEmpty(args(i)) Then
            If result = "" Then
                result = args(i)
            Else
                result = result & ", " & args(i)
            End If
        End If
    Next i
    
    SafeJoin = result
End Function