java常用类之Random

package com.Lucky.OftenClass;

import java.util.Random;

/**
 * Random :随机类
 *
 *  注意点：Math.Random()底层调用的是Random的nextDouble方法
 */
public class RandomClass {
    public static void main(String[] args) {
        Random random=new Random();

        //遍历10个随机数
        for (int i = 0; i < 10; i++) {
            //System.out.print(random.nextInt(11)+10+"\t");//10~20
            //System.out.print(random.nextInt((20)));//0~20
            System.out.println(Math.ceil(random.nextDouble()));
        }
    }
}