as result和as a result的区别

as a result相当于一个连词，一般用于句首，且要用逗号与后面的句子隔开，是因此，所以的意思

He got up very late today. As a result， he missed the first bus.他今天起晚了，结果没赶上头班车

as aresult of 是一个介词短语，后面接名词，动名词等，不能接句子，是由于，因为的意思。