Java关键字-this

Posted 2020-12-19 orz江小鱼

java.lang.Math类
里面提供了许多静态方法，供完成数学相关的操作

方法：

public static int abs(double a)//取绝对值
public static double ceil(double a)//向上取整 12.1-->13(像x轴正方向取整)-10.8-->-10.0注意返回值是double类型的
public static double floor(double a)//向下取整  12.1-->12
public static long round(double a)//四舍五入

练习

package commonclass;
//练习Math工具类
//题目：计算-10.8~5.9之间，绝对值大于6或者小于2.1的整数个数
public class PracticeMath01 {
    public static void main(String[] args) {
        double min = -10.8;
        double max = 5.9;
        int num = 0;
        for (int i = (int) min; i < max; i++) {
             if (Math.abs(i) >6 ||Math.abs(i) <= 2){
                 System.out.print(i+"	");
                 num++;
             }
        }
        System.out.println(" 
");
        System.out.println("-10.8~5.9之间，绝对值大于6或者小于2.1的整数个数有"+num+"个！");
    }
}