vba【多次元のdictionaryにキーが存在するかを調べる】

phpのissetのようなもの
vbaにはないので作りました。

Public Function isset(ByRef dic As Dictionary, ByVal KeyArr As Variant, Optional ByVal StartIndex As Integer) As Boolean
    On Error GoTo handler
    If dic.Exists(KeyArr(StartIndex)) Then
        If UBound(KeyArr) = StartIndex Then
            isset = True
        Else
            isset = isset(dic(KeyArr(StartIndex)), KeyArr, StartIndex + 1)
        End If
    Else
        isset = False
    End If
    Exit Function

handler:
    isset = False
End Function

呼び出し方

Private Sub testisset()
    Dim a As New Dictionary
    a.Add "b", New Dictionary
    a("b").Add "c", New Dictionary
    Debug.Print isset(a, Array("b", "c")) ' true
    Debug.Print isset(a, Array("b", "c", "d")) ' false
End Sub