单项选择题

以下过程的功能是向数组中增加字符，则程序中下划线处应为______
Private Sub AddToArray (arr(),arraycount%,ByVal charstring)
Dim i%, found As Boolean
found=False
For i=1 To arraycount
If arr(i)=charstring Then
found=True
Exit For
End If
Next i
If Not found Then
arraycount= arraycount+1
______
arr (arraycount)=charstring
End If
End Sub