For
控制流程语句，open语句子句或运算符取决于上下文。
For iterator = startvalue To endvalue [ Step increment ]
or
Open [ device ] "filename " For filemode As #handle
or
declare operator For ( byref stp as datatype )
语法
For iterator = startvalue To endvalue [ Step increment ]
or
Open [ device ] "filename " For filemode As #handle
or
declare operator For ( byref stp as datatype )
参考