there is no doubt whether和there is no doubt that 的区别?

2.doubt+宾语从句
（1）在否定句和疑问句中,doubt后面接that引导的宾语从句.例如：
I don”t doubt that he can finish the task on time.我相信他能按时完成任务.
Do you doubt that she will succeed?你怀疑她会成功吗?
（2）在肯定句中,doubt后面一般接whether或if引导的宾语从句.例如：
I doubt whether they can swim across the river.我怀疑他们能否游过河去.
He doubts if she will keep her word.他不敢肯定她是否会遵守诺言.
注意：在肯定句中,doubt后面也可以接that引导的宾语从句,但表示疑虑较大或“不相信”.