Java详细讲解Math和Random类中有哪些常用方法

public class Demo01 {
    public static void main(String[] args) {
        System.out.println("求-3的绝对值为：" + Math.abs(-3));
        System.out.println("求4的平方根为：" + Math.sqrt(4));
        System.out.println("求2的3次方幂为：" + Math.pow(2, 3));
        System.out.println("求2和3的最大值为：" + Math.max(2, 3));
        System.out.println("求2和3的最小值为：" + Math.min(2, 3));
        System.out.println("求9.87向下转型的数为：" + Math.floor(9.87));
        System.out.println("求9.12向上转型的数为：" + Math.ceil(9.12));
        System.out.println("求9.55的四舍五入的值为：" + Math.round(9.55));
        System.out.println("求一个0.0到1.0的随机数(不包括1.0)为：" + Math.random());
    }
}

import java.util.Random;
public class Demo03 {
    public static void main(String[] args) {
        Random random = new Random();
        //返回整型里任意一个
        System.out.println("nextInt()输出为："+random.nextInt());
        //返回大于等于0，小于9的任意一个整型
        System.out.println("nextInt(9)输出为："+random.nextInt(9));
        //返回Boolean型任意一个
        System.out.println("nextBoolean()输出为："+random.nextBoolean());
        //返回Double当中 0.0和 1.0之间的的任意一个
        System.out.println("nextDouble()输出为："+random.nextDouble());
    }
}

import java.util.Arrays;
import java.util.Random;
public class Demo04 {
    public static void main(String[] args) {
        Random random = new Random();
        byte[] bytes = new byte[5];
        random.nextBytes(bytes);
        System.out.println(Arrays.toString(bytes));
    }
}

public class Demo02 {
    public static void main(String[] args) {
        Random random = new Random(5);
        System.out.println("第一次调用：");
        for (int i = 0; i < 5; i++) {
            System.out.println(random.nextInt());
        }
        random = new Random(5);
        System.out.println("第二次调用：");
        for (int i = 0; i < 5; i++) {
            System.out.println(random.nextInt());
        }
    }
}