没错,消耗同样的内存（这里是32位）时,定点数比浮点数精度更高.浮点数的优势是同样的内存它可以表示的范围比定点数更大,但这是以损失精度为代价的!
The advantage of floating-point representation over fixed-point and integer representation is that it can support a much wider range of values.
The floating-point format needs slightly more storage (to encode the position of the radix point), so when stored in the same space, floating-point numbers achieve their greater range at the expense of precision.