Math类

1、API介绍

2、属性

public class Demo5_Math {

    public static void main(String[] args) {

        //属性
        System.out.println(Math.E);//2.718281828459045
        System.out.println(Math.PI);//3.141592653589793
    }
}

3、功能方法

public class Demo5_Math {

    public static void main(String[] args) {

        //abs() 求绝对值
        int abs = Math.abs(10);
        System.out.println(abs);//10

        int abs1 = Math.abs(-100);
        System.out.println(abs1);//100

        //max 求最大值
        int max = Math.max(10, 50);
        System.out.println(max);//50

        //min 求最小值
        double min = Math.min(2.3, 0.5);
        System.out.println(min);//0.5

        //random() 求随机值 [0 1)
        double random = Math.random();
        System.out.println(random);//0.3278848432155409

        //面试题：生成一个1～10之间随机数
        int i = (int) ((Math.random() * 10) + 1);
        System.out.println(i);

        //ceil() 向上取整
        double ceil = Math.ceil(2.3);
        System.out.println(ceil);//3.0

        //floor() 向下取整
        double floor = Math.floor(3.9);
        System.out.println(floor);//3.0

        //round() 四舍五入
        long round = Math.round(2.3);
        System.out.println(round);//2
        //method_属性();

    }
}