java基础 Math

 1 package cn.mantishell.day08.demo04;
 2 
 3 /**
 4  * java.util.Math类是数学相关的工具类，里面提供类大量的静态方法，完成与数学运算相关的操作
 5  *
 6  * public static double abs(double num);获取绝对值
 7  * public static double ceil(double num);向上取整
 8  * public static double floor(double num);向下取整
 9  * public static long round(double num);四舍五入
10  */
11 public class Demo03Math {
12     public static void main(String[] args) {
13         //获取绝对值
14         System.out.println(Math.abs(-2.5));//2.5
15         //向上取整
16         System.out.println(Math.ceil(3.9));//4.0
17         System.out.println(Math.ceil(3.1));//4.0
18         System.out.println(Math.ceil(3.0));//3.0
19 
20         System.out.println(Math.floor(10.9));
21 
22         System.out.println(Math.round(2.6));
23     }
24 }