Math.round()：将括号内的数+0.5，然后向下取整 11.5 + 0.5 = 12，向下取整即12 -11.5 + 0.5 = -11，向下取整即-11 相关文章： 2021-11-04 2021-08-24 2022-02-07 2021-12-09 2021-07-04 2021-05-12