四舍五入函数的区别
round、floor、ceil区别 1 round
round 向最接近的整数取整，如果包含0.5则向右取值
System.out.println(Math.round(2.1));
System.out.println(Math.round(2.5));
System.out.println(Math.round(2.6));
System.out.println(Math.round(-2.1));
System.out.println(Math.round(-2.5));
System.out.println(Math.round(-2.6));
2 floor
floor 不大于该数的最接近整数
System.out.println(Math.floor(2.1));
System.out.println(Math.floor(2.5));
System.out.println(Math.floor(2.6));
System.out.println(Math.floor(-2.1));
System.out.println(Math.floor(-2.5));
System.out.println(Math.floor(-2.6));
3 ceil
ceil 不小于该数的最近进整数
System.out.println(Math.ceil(2.1));
System.out.println(Math.ceil(2.5));
System.out.println(Math.ceil(2.6));
System.out.println(Math.ceil(-2.1));
System.out.println(Math.ceil(-2.5));
System.out.println(Math.ceil(-2.6));
答案
2 3 3 -2 -2 -3
2.0 2.0 2.0 -3.0 -3.0 -3.0
3.0 3.0 3.0 -2.0 -2.0 -2.0
