API(Math)

public class mathDemon1 {
public static void main(String[] args) {

        public static int abs(int a)//绝对值
        public static double ceil(double a)//向上取整
        public static double floor(double a)//向下取整
        public static int max(int a,int b)//求最大值
        public static int min(int a,int b)//求最小值
        public static double pow(double a,double b)//求a的b次幂
        public static double random()//求随机数[0.0,1.0)
		public static int round(float a)//四舍五入
        public static double sqrt(double a)//开平方
        public static int cbrt(double a)//开立方根
    
    //1.绝对值(范围int的最小值到int的最大值)
    System.out.println(Math.abs(-10));//10
    //2.向上取整,往数轴的正方向取整
    System.out.println(Math.ceil(10.1));//11.0
    System.out.println(Math.ceil(-10.1));//-10.0
    //3.向下取整,往数轴的负方向取整
    System.out.println(Math.floor(10.9));//10.0
    System.out.println(Math.floor(-10.9));//-11.0
    //4.求最大值
    System.out.println(Math.max(10,20));//20
    //5.求最小值
    System.out.println(Math.min(10,20));//10
    //6.求a的b次幂
    System.out.println(Math.pow(2,3));//8.0
    //7.求随机数[0.0,1.0)
    System.out.println(Math.random());
}

}

输出:
10
11.0
-10.0
10.0
-11.0
20
10
8.0
0.6589054483886688