Java Math floor round ceil 函数
public final class Math extends Object
public static double floor(double a)
public static long round(double a)
public static int round(float a)
public static double ceil(double a)
floor 返回不大于的最大整数;
ceil 则是不小于他的最小整数;
round 它表示“四舍五入”，算法为Math.floor(x+0.5)，即将原来的数字加上0.5后再向下取整;
所以，Math.round(11.5)的结果为12，Math.round(-11.5)的结果为-11;
| Math.floor | Math.round | Math.ceil | |
|
1.4
|
1.0
|
1
|
2.0
|
|
1.5
|
1.0
|
2
|
2.0
|
|
1.6
|
1.0
|
2
|
2.0
|
|
-1.4
|
-2.0
|
-1
|
-1.0
|
|
-1.5
|
-2.0
|
-1
|
-1.0
|
|
-1.6
|
-2.0
|
-2
|
-1.0
|
